摘要:

Fowl paralysis is generally considered to be a disease of birds over three months of age. In the present paper data are presented on 45 out of 244 chicks (18.4%), which developed clinical symptoms of fowl paralysis before 90 days of age. Of these, 20 were inoculated and 25 were not inoculated. Forty-two of the 45 chicks (93.3%) showed lesions in the nervous system. Nine chicks (20%) showed lymphomatous tumors.Seventeen of the 45 cases (37.7%) occurred in chicks less than 60 days of age; the same number of cases occurred between 60 and 74 days of age; and 11 cases (24.4%) occurred between 75 and 89 days of age. The mean age of all chicks that developed paralysis was 64.4 days.The fact that typical fowl paralysis occurred in one chick at 37 days, and in several from 40 to 44 days of age, would indicate that the disease may develop at a very rapid rate.

ISSN:1923-4287    

DOI:10.1139/cjr33-026

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

Swine erysipelas has been recognized in widely separated districts in Saskatchewan, the disease having appeared in the acute, sub-acute and chronic forms.The organism has been isolated from a number of cases and positive serological reactions obtained in others.The organism isolated has been used to inoculate healthy pigs and in this way the disease has been reproduced.

ISSN:1923-4287    

DOI:10.1139/cjr33-027

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

One adult Cestodarian, 53 adult Cestoda and 24 larval Cestoda are known to occur in Canadian animals. The majority of the Cestoda are distributed among the Dibothriocephaloidea and Taenioidea.Of the Cestoda, 29 of the adult species are represented in Europe, 14 are recorded elsewhere only in the United States, 6 are recorded only in Canada and 4 are unassignable. Of the 24 larval forms, 14 and one doubtful form are also European, 3 and two doubtful forms are recorded elsewhere only in the United States, 2 occur also in Japanese waters and 2 are not assignable.An attempt is made to evaluate the economic status of the cestodes of the area.

ISSN:1923-4287    

DOI:10.1139/cjr33-028

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

A duck obtained from a farm near Ottawa, Canada, was found on post-mortem examination to be parasitized by a hitherto unreported nematode. No males were discovered but an examination of the nine females obtained revealed certain characteristics which appeared to justify the formation of a new species, for which the nameTetrameres cramiis proposed.

ISSN:1923-4287    

DOI:10.1139/cjr33-029

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The occurrence, hosts and symptoms of a hitherto undescribed root rot ofMelilotus,MedicagoandTrifolium, and the relation of temperature and the reaction of substrate to growth of the pathogenPlenodomus melilotiare discussed, and its pathogenicity demonstrated. It is suggested that the disease be called "brown root rot".Evidence is that the hosts mentioned are susceptible only during the winter and early spring dormancy stage. Normal roots of sweet clover, when frozen at −4 °C. for four days and subsequently kept at 2–3°, 9° and 16 °C., did not become susceptible. The brown root-rot disease is distinct from true winter injury resulting from insufficient hardiness to cold.The temperature range for vegetative growth and pycnidia ofP.melilotiis from 0° to 27 °C., with optimum between 15° and 17 °C. Increasingly good growth occurs from 2 °C. to optimum temperature. Severe lesions are produced at 2–3°, 9° and 16 °C. The optimum pH value for growth in potato dextrose decoction is about 6.2, the other limits being approximately pH 3.2 and 8.2. Soils with an alkaline reaction apparently are unfavorable.The disease is characterized by brown lesions, on or within which are an abundance of black to dark brown pycnidia. These bodies, 0.5 to 2 mm. in longest diameter, may have one or more spore bearing chambers. Each chamber may have one to several ostioles, through which the one-celled spores, averaging 5.2 × 2.84 μ, exude. The hyphae do not bear spores.Dissemination of the pathogen by seed would not seem to be of practical importance. Control by crop sanitation is recommended, at least until varieties more resistant are available.

ISSN:1923-4287    

DOI:10.1139/cjr33-030

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

A survey was made of certain wild and cultivated grasses in Alberta in order to ascertain to what extent they are harboring fungi capable of causing foot rots of wheat. Quack grass,Agropyron repens, and western rye grass,Agropyron tenerum, were found to be particularly important in this respect. Both were found heavily attacked under natural conditions with strains of the take-all fungus,Ophiobolus graminis, which proved capable of causing as severe damage to wheat as strains from wheat. Strains ofHelminthosporium sativumwhich proved highly pathogenic to wheat were also isolated from these two grasses. Strains ofFusariumobtained fromA.repensandA.richardsoniicaused little or no damage to wheat.Agropyron repensis already an important weed in central Alberta. It was found infesting cultivated fields in summerfallow as well as those in crop. In summerfallow this weed appears to encourage the survival ofOphiobolus graminis, while in wheat fields infected quack grass was found associated with severe take-all damage to the crop.Agropyron tenerumis one of our most popular forage grasses and occurs commonly as a wild native plant in Alberta. Observations indicate that in the moister parts of the province wheat following this grass in rotations may be severely injured by take-all. In a rotation at the University of Alberta, wheat showed little or no take-all damage after timothy and alfalfa, moderate damage after brome grass and severe damage after western rye grass. In this experiment western rye grass itself was almost killed out prematurely in all replicates, apparently by the take-all fungus.Artificial inoculation of the various grasses was made with wheat strains of foot-rotting fungi by adding inoculum to the soil. All species ofAgropyrontested including crested wheat grass,Agropyron cristatum, proved highly susceptible toOphiobolus graminis, moderately susceptible toHelminthosporium sativum, but only slightly susceptible toFusarium graminearum, though the latter was responsible for considerable non-emergence of the seedlings.Bromus inermisandB.ciliatusproved quite susceptible to all three pathogenes.Hordeum jubatumwas heavily attacked byOphiobolus graminisbut not by the other two fungi.Avena sativawas not attacked byO.graminisand only slightly byH.sativumandF.graminearum, while timothy,Phleum pratense, appeared immune from all three fungi.

ISSN:1923-4287    

DOI:10.1139/cjr33-031

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

Viscosity measurements were made with the MacMichael viscosimeter on leached and unleached suspensions of 11 experimentally milled flours representing the range 8.2–18.3% protein. The leached flour values gave the least satisfactory differentiation. The actual measurements made on unleached suspensions, or the response to acidulation or to increased flour concentration of the unleached suspensions, gave as much differentiation as the bromate baking test. Of the latter three the simple determination of viscosity of the unleached suspensions is recommended as the most rapid.

ISSN:1923-4287    

DOI:10.1139/cjr33-032

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

Microbiological studies of samples from the separate horizons and from different depths of soils of the Appalachian upland podsol group show that the activity of the micro-organisms is dependent upon the organic-matter relations in the horizons. The organic-matter horizon is biologically the most active, as shown by analyses for carbon dioxide, nitrate nitrogen, numbers of bacteria, and production of ammonia from urea. Evidence is submitted that the reduced activity of the leached layer and the horizons of accumulation is not due to toxic compounds produced by leaching of the organic matter.

ISSN:1923-4287    

DOI:10.1139/cjr33-033

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

When pairs of colors fall upon the same area of a retina it is impossible to separate the receptor actions in the retina from those that take place in the visual centres of the cortex. If the separate colors, however, are allowed to fall upon the two eyes, the fusion color effects must be attributed to the sensations in the cortex.In this investigation the binocular fusion of complementary colors into white is confirmed, as well as the binocular fusion of red and green colors into yellow. The sensation of yellow is therefore proved to be compounded of the fundamental sensations, red and green.The binocular oscillation or rivalry of colors was specially studied and shown to be due not to fluctuations of attention, but probably to the oscillation of the neural processes of inhibition and facilitation. The oscillation of colors is thereby connected with other phenomena of vision.

ISSN:1923-4287    

DOI:10.1139/cjr33-034

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The viscosities of acetaldehyde, of paraldehyde and of mixtures of these are given at 15 °C., using materials freshly distilled out of contact with oxygen.

ISSN:1923-4287    

DOI:10.1139/cjr33-035

出版商:NRC Research Press    

年代:1933

数据来源: NRC