摘要:

A complete redescription ofCephalobellus brevicaudatum(Leidy, 1851) Christie, 1933, is given; its specific relationship is discussed, and a key to the species of the genusCephalobellusis given. It is proposed thatThelastoma indianaBasir, 1940, andCephalobellus lloydiBaylis, 1946, be regarded as synonymous withC.brevicaudatum.

ISSN:1923-4287    

DOI:10.1139/cjr49d-004

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The serum vitamin A level of sexually immature pullets was increased threefold to fourfold by intramuscular injection of 24 mgm. estradiol dipropionate plus 4.5 mgm. testosterone propionate administered in six equal doses over a 12-day period as compared with the level in similar pullets receiving only testosterone propionate. It is suggested that gonadal hormone activity is one of the factors that regulate serum vitamin A levels in the domestic fowl.

ISSN:1923-4287    

DOI:10.1139/cjr49d-005

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

A new species of an ascidian,Pycnoclavella stanleyi, is described. It occurs in some abundance near low tide level at Pacific Grove, Calif. It differs fromP.aurilucensGarstang, known only from the western end of the English Channel, mainly in the character of the colony rather than that of the individual zooid or tadpole larva. Colonies are flat, incrusting, heavily impregnated with sand, have a gelatinous matrix, and exhibit some orange pigmentation. Colonies ofP.aurilucensare without sand, have a leathery texture, are green, and are not intertidal. Both species have zooids with seven rows of gill slits on each side, a posterior vascular budding stolon as inClavelina, and a tadpole larva with an ocellus but not an otolith.

ISSN:1923-4287    

DOI:10.1139/cjr49d-006

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Two definite types of cells, provisionally designated dark and light, in accordance with the degree of their superficial argyrophilism, are revealed in the terminal bronchiolar epithelium of the albino mouse by supravital silverization. The dark cells are ciliated, and scattered among the light unciliated cells as singles, pairs, triads, or larger groups to form a striking and characteristic surface pattern. The cuticles of the dark cells, far outreached by the neighboring light cells, appearen faceas dense crowds of small uniform golden brown granules. Viewed laterally these show as pairs in vertical alignment, and make two layers with a thin lighter band between. The sides and bases are indicated by deposits of black grains. Near the sharply marked margin of the definitive epithelium the dark cells are shorter, more dispersed, and formed like truncated pyramids with narrow densely impregnated apices on some of which are single delicate points instead of discrete cilia. The light cells have bulging villuslike free ends and make flutings on the contiguous dark cells. Small silverized particles sparsely stipple their air surfaces and rounded plaques crown their summits. A similar dicellular picture is found in the terminal bronchiolar epithelium of the golden hamster.

ISSN:1923-4287    

DOI:10.1139/cjr49d-007

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Three series of compounds have been prepared and compared for the insecticidal activities against German roaches and houseflies. The substituted 2,2-diphenyltrichloroethanes and substituted benzohydrols have been found to have comparable activities on roaches. The substituted 2,2-diphenyltrichloroethanes alone had insecticidal properties against houseflies. The benzophenone derivatives were ineffective against both groups of insects.

ISSN:1923-4287    

DOI:10.1139/cjr49d-008

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Records of the area trapped and of legally caught furs in the Chapleau district, Ontario, have been made for the seasons 1941–42 to 1946–47. From these records the area required to produce one harvested animal has been computed for most species, which should be of considerable value to persons concerned with fur production in Canada. These figures should also be useful to students of animal populations since they take into account, at least in part (specific areas actually trapped), the variation in trapping pressure that cannot be reflected in figures based on total numbers taken from large areas. This six year period seems sufficient to indicate significant trends in populations, which in certain cases might be predicted by study of past trends of province-wide returns.During the six year period the average return value for each square mile trapped was $16.90, which netted each trapper using one township an average of $607.00 each year. The average total annual fur resources amounted to $74,000.00.The distribution of the catch of marten and fisher in the district suggests that the Chapleau Crown Game Preserve may be influencing the catch of these two species in nearby territories.

ISSN:1923-4287    

DOI:10.1139/cjr49d-009

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Three groups of goldfish were fed diets containing 25% fat. The diets for the three groups differed in the degree of unsaturation of these fats. Pilchard oil (iodine value 181.7), herring oil (iodine value 128.4), and lard (iodine value 66.2) were the fats used. Heat tolerance of the fish was then tested by holding them at a constant high temperature and observing the time of death. Variations in the ability of the groups to withstand high temperature were correlated with differences in the degree of unsaturation of their extracted fats. The iodine value of the herring oil diet was very close to that of the fats of the goldfish prior to feeding and no change in the value for fish fed on this diet was observed. Each of the other two diets changed the degree of unsaturation of the goldfish fats by approximately 54% of the maximum theoretical change. These changes modified the heat resistance of the fish. The degree of modification of heat tolerance, however, cannot be strictly correlated with the degree of change of unsaturation of fats and it is concluded that factors associated with differences in melting point rather than melting point of the fat itself are probably involved in heat resistance.

ISSN:1923-4287    

DOI:10.1139/cjr49d-010

出版商:NRC Research Press    

年代:1949

数据来源: NRC