摘要:

Laboratory experiments are described that demonstrate that the antennal aristae of muscoid Diptera are sensitive to slight fluctuations in pressure, acting as external baroreceptors. Further experiments show that the increase in activity exhibited by flies at low pressure is of a kinetic nature, lacking any directional element, while the reaction of flies to manually-produced pressure waves that vibrate the aristae is tactic in a baronegative sense. It is suggested that the erratic prethunderstorm flight of muscoid Diptera results largely from such a baronegative response to localized pressure changes. This suggestion is based on laboratory observations of the reactions of flies under simulated storm pressure patterns.

ISSN:1923-4287    

DOI:10.1139/cjr46d-008

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

A study of 624 specimens ofBonasa umbellusshows that variation in the species in eastern North America consists in a loss of red pigment from south to north. Westward in Canada there is a reduction of black resulting in paleness and greyness. This variation resolves itself into eight subspecies, which can be grouped into two "super-subspecies," based on the potential for redness. The ratio of colour phases and "trimming" of most Canadian races has been worked out. The type locality ofB.u.umbelloideshas been determined as Belvedere, Alta. The racecanescensof Todd is found valid and the evidence is presented by the application of a simple quantitative tone or value scale. Its range extends from James Bay to central and western Ontario, consequently the range ofB.u.togatais greatly restricted in Ontario. Minor refinements of the ranges of other races are presented.The incidence of the red phase is higher in females, the percentages of occurrence suggesting that this phase is a sex-linked recessive character. A variation designated as "copper-trimmed" is more prevalent in males and may be controlled by a dominant sex-linked factor.

ISSN:1923-4287    

DOI:10.1139/cjr46d-009

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

These records of 78 species of marine fishes collected in British Columbia waters include: nine not previously known in the region; the northernmost recorded range of 14 species; new distributions of 76 species within the province; and a bibliography of all published papers dealing with the Canadian distribution of the species discussed.

ISSN:1923-4287    

DOI:10.1139/cjr46d-010

出版商:NRC Research Press    

年代:1946

数据来源: NRC