ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07788.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary.1 It is pointed out that the classification of geckos has remained unstable during the last eighty years.2 The eyelids and spectacles of geckos have been misunderstood; the eyelids are primitive, the spectacle is secondary.3 The majority of geckos have a pure rod retina in association with nocturnal habits, the rods derived by transmutation of cones.4 Two types of vertical pupil are distinguished, that with a straight edge and theGekko‐type with three lobes on anterior and posterior margins.5 Diplodactylushas a straight vertical pupil,Phyllodactylus a Gekko‐type pupil, several species are reallocated.6 Narudasiais revived and distinguished fromQuedenfeldtiaon pupil shape.7 Gymnodactylusis redefined and restricted to South American forms with straight vertical pupil.8 Phyllurusis used for Australasian “Gymnodactylus” with straight vertical pupil.9 Cyrtodactylusis revived for Old World “Gymnodactylus” withGekko‐type pupil.10 Wallsaurusgen. nov. is proposed forGymnodactylus horriduswith straight padless digits andGekko‐type pupil.11 Arrangement of geckos as a superfamily Gekkonoidea with three families is proposed.12 Boulenger's Eublepharidae is revived for geckos with true eyelids with the addition ofHolodactylusandAeluroscalabates.13 Sphaerodactylidae fam. nov. is proposed for procoelous geckos with spectacle includingColeodactylus, Gonatodes, Lepidoblepharis, andPseudogonatodes.14 The family Gekkonidae is restricted to amphicoelous geckos with spectacle and is divided into two subfamilies.15 Diplodactylinae subfam. nov. is proposed for Gekkonids with straight vertical pupil, twenty‐two genera are placed here.16 Subfamily Gekkoninae is restricted to geckos withGekko‐type pupil, thirty‐eight genera are placed here. Nine genera remain unplaced.17 Amphicoelous geckos appear also to have the two elements of the neural arch separate.18 The position ofUroplatusis discussed.19 The Eublepharidae are relicts of an archaic specialized group in old stable land areas.20 The Sphaerodactylidae are a strictly New World group centred on the Caribbean.21 The Diplodactylinae have a wide broken distribution and appear largely to have been supplanted by the Gekkoninae.22 Aristelligeris a relict of primitive archaic type in the Antilles.BavayaandRhacodactylus, also of peripheral distribution (New Caledonia), may be related toAristelliger.23 The Gekkoninae have a wide range and it is suggested that there was an original dispersal of arboreal forms and that there has been independent reversal to terrestrial habits in several regions.24 The desert region of N. Africa and S.W. Asia contains a wealth of padless terrestrial geckos.25 Madagascar has eleven genera of geckos all with pads and none archaic.26 The Oriental Region has a wealth of Gekkoninae, no Diplodactylinae.27 South Africa and Australia both have notable groups of Diplodactylinae.28 The problem of the occurrence of aTarentolain Cuba is discussed.29 The view that the procoelous condition is primitive and the amphicoelous condition secondary in geckos is upheld.30 It is argued that geckos whilst ancient are not primitive.31 A tentative outline of the evolutionary history of geckos is put forward.32 Evidences for parallel evolution in geckos are discussed in respect of the adaptation of the eye to dim lighting conditions and the secondary reversion to terrestrial habits with loss of digital pads.33 It is argued that the cases of parallel evolution are much better explained in terms of evolutionary opportunity as a relationship between organism and environment than in terms of any innate tendencies.34 In several stocks there is an increase over the “st

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07789.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary1 Collections of the gonads of desert birds which were made in localities during, and soon after, severe drought revealed striking differences in reproductive development.2 Comparatively meagre rainfall and the resultant creation of relatively beneficial conditions has a more stimulating effect on the male than on the female cycle.3 The failure of the females to respond leads to a disturbance of the normal sequence of events in the male gonad and abnormal conditions, similar to those found in Arctic and other non‐breeders, were observed in the undischarged testis. These are not readily explained by the known facts concerning the hypophysial/gonad relationship in vertebrates.4 Desert birds have evolved an unusually high degree of nomadic mobility to defeat droughts. They exhibit a further vital physiological aspect of drought adaptation in that their sexual cycles can respond quickly to rainfall, or its effects, so that nidification may begin within a few days of heavy precipitation, irrespective of daylength and light increment. On the other hand, the gonads may remain inactive, in the true sense of the word, and reproduction can be inhibited for a succession of seasons during a prolonge

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07790.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07791.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary.A new species ofRaillietiella, the first to be recorded from the family Agamidae or from an Australian host, is described.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07792.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary.A description is given of the female and the previously unknown male ofSeius degeneransBerl., 1889. This species is the type‐species of the genusIphiseiusBerl., 1921. A comparison is made of the generaIphiseiusandTyphlodromusScheuten. The former is transferred from the subfamily Podocininae to the subfamily Phytoseiina

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07793.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary.The unusual occurrence of cysticercoids in mammalian liver is recorded. Larval forms ofHymenolepis nana fraternaare described from the liver of a Darling's Mole Rat, and comparisons made with cysts from experimentally infected white mice and with adult material.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07794.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary.The eggs of the Bass,Morone labrax(L.), in British waters, are larger than those of the Mediterranean eggs observed by Bertolini (1933).These eggs hatch on the fourth day, and the mean length of newly hatched larvae is 3.83 mm. By the end of twenty‐four hours this length has increased to 4.85 mm., by the third day to 4.98 mm., by the fourth day to 4.99 mm. and on the tenth day the mean length is 5.61 mm.During the first twenty‐four hours, the early post‐larval stages rest for long periods at the surface of the water. On the third day the larvae begin to sink slowly when at rest, and normal horizontal swimming is commenced on the sixth day. By the tenth day the larvae swim with the mouth open.From the observed rate of growth of these reared larval stages, it is likely that those taken in the plankton hauls off the Eddystone during the period 1925–1933 (Russell 1935) were from three to fifteen d

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07795.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary.1 In natural populations parthenogenetic egg production inDaphnia magnaStraus is directly related to size.2 Previous workers have shown that the number of parthenogenetic eggs produced during the life of a female increases in the early broods and decreases in later broods.3 Egg production and size are positively correlated in the first adult instar, both under constant conditions and with varying food.4 The size of the young liberated varies with maternal age, the third brood consisting of young of a larger average size than earlier or later broods.5 The initial size of the young liberated influences the instar in which maturity is reached.6 The probable effects of maternal age on growth, maturation and longevity of the young ar

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07796.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Summary.1 The six species of caddis larvae selected for study were collected from the River Blyth, Northumberland, a small river with alternate shallow swift‐flowing and deeper slow‐flowing stretches. The species selected wereRhyacophila dorsalis, Wormaldia subnigraandHydropsyche instabilisfrom swift water,Anabolia nervosaandPolycentropus flavomaculatusfrom slow‐flowing water andStenophylax stellatus, a species which is generally distributed. Of these species,Anabolia nervosaandStenophylax stellatusare case‐bearing larvae andHydropsyche instabilis, Wormaldia subnigraandPolycentropus flavomaculatusspin nets or snares for food collection. Rhythmic undulatory current‐producing movements of the abdomen are made by all the larvae exceptRhyacophila dorsalisandWormaldia subnigra.2 Accurate identification entailed rearing the larvae to the adult state.Rhyacophila dorsalis,Wormaldia subnigraandHydropsyche instabilis, species from swift waters which do not live long in still‐water aquaria, were successfully reared in small aquaria in which the water was continuously stirred by means of rotary stirrers.3 The larvae may be arranged in the following ascending order of ability to resist the flow of water when exposed to the full force of the current in an experimental channel:—1 Polycentropus flavomaculatus.2 Anabolia nervosa.3 Stenophylax stellatus.4 Wormaldia subnigra.5 Rhyacophila dorsalis, Hydropsyche instabilis.4 The behaviour of the net‐ and snare‐spinning larvae in aquaria showed thatHydropsyche instabilisandWormaldia subnigralarvae only spin typical nets in flowing water and that the former will spin nets in slower‐flowing water than will the latter.Polycentropus flavomaculatuslarvae will spin snares in still water.5 Oxygen determinations on samples of water from swift‐ and slow‐flowing areas of the River Blyth showed only small differences. Further, under certain circumstances water from swift‐flowing reaches may have a lower dissolved oxygen concentration than water from slow‐flowing reaches.6 The minimum oxygen concentration, i.e. that at which larvae become immobilized, was determined experimentally for each species in still water. This concentration was relatively high for the swift‐water speciesRhyacophila dorsalis, Wormaldia subnigraandHydropsyche instabilis, but in stirred water it was similar to that obtained for the other species in still water.7 InHydropsyche instabilis, Polycentropus flavomaculatus, Stenophylax stellatusandAnabolia nervosalarvae decreasing oxygen concentration tended to increase the number of undulatory abdominal movements. InHydropsyche instabilisandPolycentropus flavomaculatuslarvae the number of movements was reduced by an increase in the rate of stirring of the water.8 In conclusion, the importance of water flow in determining the distribution of these larvae is stressed. Larvae unable to withstand the force of the current are unable to inhabit swift waters (Polycentropus flavomaculatus, Anabolia nervosa). Some larvae are dependent upon current for feeding (Hydropsyche instabilis, Wormaldia subnigra), and larvae readily immobilized at a relatively high oxygen concentration in still waters (Rhyacophila dorsalis, Wormaldia subnigra, Hydropsyche instabilis)

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1954.tb07797.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY