摘要:

SYNOPSIS.The effects of some environmental influences on the cycle ofTrypanosoma diemyctyliinTriturus v. viridescensare described. Bleeding of the host produced a reduction in the number of trypanosomes but did not affect their growth rate. The temperature at which the host was maintained affected the cycle of the trypanosomes. The length of the post‐inoculation latent stage increased from 24 hours at 25°C. to an indefinitely long time at 5°C. The trypanosomes were found to be dimorphic. Adult parasites of the short form had a range of 45–75 μ and those of the long form of 76–116 μ. Growth rate of the trypanosomes was inhibited or greatly retarded at temperatures of 10°C. or lower and was greatest at 25°C. The size attained by the parasites and the number of parasites were greatest at 15°C. At this temperature the infection was pathogenic and the dimorphic parasites were in their long form. At the higher temperatures (20–25°C.) the infection was non‐pathogenic with the trypanosomes in their short form.The infection is primarily one of adult newts. Experiments indicated that the larvae were resistant to the trypanosomes at all temperatures while the red efts were not. The latter are usually free from the trypanosomes because they are not exposed to them. Attempts to infect other newts and to locate any cryptic stages by the injection of blood and tissues from infected newts gave negative results.Starvation, sodium salicylate, and treatments used to control fungus infection of the newts had no detectable effects on

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02546.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.Association of gamonts ofPyxinia crystalligeratakes place in the midgut of its beetle host,Dermestes vulpinus.At 25°C. the development of gametocysts to the point of liberation of sporocysts is completed between about 15 hours and 27 hours after the gametocysts are deposited with fecal material. Dehiscence is favored by relative humidities of 0% to 90%, but is not favored by a relative humidity of 100%. During the early development of the gametocysts outside the host, the crystals and paraglycogen granules in the cytoplasm of the associated gamonts become concentrated in large masses. The gametes are formed at the periphery of the gamonts. After fusion of the gametes takes place and the sporoblasts begin to develop, the residual cytoplasm containing the inclusions moves outward to form a continuous layer next to the gametocyst envelope, so that the sporoblasts become crowded into a central core. A few hours before dehiscence is initiated a clear area appears on the upper side of the gametocyst. The contents of the gametocyst begin to shrink away from the envelope except in the region of the clear area. Eventually the sporocysts emerge through the clear area and press against the envelope of the gametocyst, causing formation of a conical papilla in the envelope. With continued pressure from the sporocysts, the papilla ruptures at its tip, and the sporocysts emerge in a continuous thread until dehiscence is completed. The thread of sporocysts may attain a length of about 11 mm

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02547.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.Pseudomicrothorax dubius, a rather rare protozoon assigned by Kahl to the trichostome order of ciliates, has been found and positively identified for the first time in America, and its morphology and morphogenesis have been studied in detail with the aid of modern techniques. The Chatton‐Lwoff silver impregnation method is considered indispensable in acquiring an understanding of the ciliate's infraciliature: both its anatomy in the mature vegetative animal and its activities during the morphogenetics of binary fission.Stomatogenesis is of a complex type, considered here as “semi‐autonomous” in nature, although a single, true stomatogenous meridian also is involved. Details of this explicit morphogenetic phenomenon are offered.The presence of a true zone of three adoral membranelles, never before recognized with any accuracy in this ciliate, a buccal cavity and associated structures, and the mode of stomatogenesis have led the writers to propose transfer of the genusPseudomicrothoraxfrom the Trichostomatida to the order Hymenost

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02548.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.The rather rarely found holotrichous ciliatePseudomicrothorax dubius, generally considered in the most authoritative literature to be a member of the order Trichostomatida, more likely belongs in the Hymenostomatida. Its curious combination of trans‐ordinal characteristics, however, makes difficult exact systematic allocation of it and of the congeneric speciesP. agilis.The provocative morphological features include: a gymnostome‐like cytopharyngeal “basket”; a tetrahymenal buccal apparatus, with membranelles comparable with those of primitive hymenostomes; an advanced semi‐autonomous type of stomatogenesis; and sensory bristles, flattened rigid form, and restricted ciliature reminiscent of certain spirotrichs. Brief discussion is presented concerning the influence of modern ideas of ciliate classification upon what is considered the proper taxonomic position of

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02549.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.The steps leading to purine ring closure were examined inStrigomonas oncopelti.The flagellate has an obligate adenine requirement (hypoxanthine and guanine are inert) when grown withoutp‐aminobenzoic acid. The imidazole counterpart of adenine but not the imidazole counterpart of hypoxanthine was active. A pathway for purine biosynthesis compatible with these results is sketche

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02550.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.Studies of the body ciliature ofBalantidium coliandB. caviae(?) after Breslau's opal‐blue and Klein's silver nitrate techniques revealed a preoral‐dorsal suture area where some of the ciliary rows fail to reach the peristomial margin. The incomplete kineties ranged up to a dozen in number and were variable in arrangement. In a count of 100 specimens ofB. caviae(?) the incomplete kineties were at the right of the suture in 39, at the left in 24 and on both sides of the suture line in 37. At the posterior end not many kineties reach the pole but no sutural pattern was seen in that region. Scattered irregularities in the ciliary rows were sometimes seen.Studies of the oral region tend to confirm the view of Fauré‐Fremiet that the peristomial ciliature consists of short rows of cilia which are continuations of the anterior body kineties. Membranelles were not found. Thus, some species ofBalantidium, at least, show affinities with the Holotricha in agreement with Nie and Fauré‐Fremiet.Fission commonly produces two equal‐sized daughters but many cases of unequal division were observed. In both these species conjugants are much smaller than vegetative animals and two preconjugant divisions are indicated, the first of which may be unequal.During the early stages of fission, the anterior ends of the kineties of the posterior daughter change direction, becoming oblique in the fission zone. In this region the kinetosomes multiply; possibly some of the kineties also divide but evidence for this is incomplete. No evidence of reorganization at the anterior end of the anterior daughter was seen.Attempts to infect hamsters withB. coliandB. caviae(?) failed. No parasites were found in two collared peccaries repeated

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02551.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.A comparative study of five species ofTetrahymena, including thirteen strains, was made to ascertain their ability to act as facultative parasites. A variety of experimental hosts, including both vertebrates and invertebrates, were inoculated with axenic cultures of protozoa. Infections were numerous in both larval and adult insects. Tissues of living vertebrates were invaded by one species ofTetrahymenathrough artificially produced wounds.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02552.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.A new fresh water species ofActinosphaeriumis described, the fourth member of the genus. Some of the more significant of its diagnostic traits are: 1) the Actinophrys‐like nuclei with peripheral nucleolar granules and without central rosette‐shaped nucleoli, 2) the occurrence of some nuclei in the ecto‐endoplasmic border and the insertion of axial filaments on them, and 3) the low ratio of endoplasm to ecto

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02553.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.Unabsorbed, complement‐inactivated antisera produced in rabbits were used in an immobilization system to study the serology of 31 strains ofTetrahymena pyriformisgrown in axenic cultures at 26°C. Fourteen serological “groups” were found: 1. “H”: H, E, S, GC, L3, W, T, GHH, G1‐R and sublines W‐P and T‐P; 2. “PR”: PR; 3. “GL”: GL; 4. “LR”: LR; 5. “L1”: L1 and L2; 6. “GP”: GP and Ch‐S; 7. “WH”: WH6, WH14 and WH52; 8. “N”: N and HS; 9. “Y”: Y and TC; 10. “AA”: AA1, AA2 and AA4; 11. “F”: F and BF; 12. “Gf‐J”: Gf‐J; 13. “EZ”: EZ; 14. “Lava”: Lava. Not all of these “groups” were completely distinct; weak or variable cross‐reactions occurring for particular cultures and antisera during the course of several years of observation suggested a relationship in terms of serotype potentialities, for strains in groups 1 and 2, and in groups 2, 3, 4, 5, and 6. Non‐reciprocal cross‐reactions are tentatively explained in terms of population fluctuations of serotype within particular cultures; several other suggested explanations remain possible. On the whole, however, the strains remained remarkably stable in dominant serotype.Observations onTetrahymenain paralyzing antisera, with respect to the extrusion of a gelatinous exudate, in general confirmed previous observations by others. “Chain” formation was noted upon recovery, under conditions suggesting that the chains do not always derive entirely from incomplete cytokinesis of dividing organisms but that at least sometimes an aggregation of separate individuals is also involved. Synchronized division was observed for recovering organisms. A gelatinous material was obtained by centrifugation of a large number of individuals; this material provided a degree of protection to the organisms against antiserum effects while other colloidal materials did not, but the protective effects proved nonspeci

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02554.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SYNOPSIS.In cultures of the marine dinoflagellateGonyaulax polyedragrown with alternating light and dark periods of 12 hours each, at least 85% of all cell divisions which occur in a day take place during a 5‐hour period spanning the end of the dark period and the beginning of the light period. A very distinct maximum in the number of recently divided cells occurs at about the time the light period begins.This diurnal periodicity in cell division is lost after 4 to 6 days in continuous bright light, but will persist for at least 14 days in continuous dim light. The period of approximately 24 hours under constant conditions is only slightly altered by varying light intensity and temperature, both of which factors are known to affect markedly the generation time. The time at which cell division occurs is therefore postulated to be controlled by some sort of rhythmic or clock mechanism.Similarities between the cell division rhythm and the endogenous rhythm of luminescence in this organism are discussed. The occurrence of a glow, or steady light emission of low intensity, at about the time of cell division, is described, and it is suggested that this glow may result from cellular changes accompanying certain stages of cell divisio

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1958.tb02555.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY