( Ixxxv ) 



the saucer, just skimming the surface of the water, in the 

 manner of a frightened water-fowl such as the Grebe. 



" Their progression under water— comparatively slow, and 

 effected by means of a series of jerks— was clearly due to 

 flying rather than swimming, but they also made use of their 

 legs, the posterior pair being kicked out behind simultaneously 

 with the movement of the wines 



" We found that individuals kept in confinement always 

 preferred to crawl about among the Spirogyra in preference 

 to any other water plant. Several were kept alive by Mr. 

 Britten for about a week. 



" One male was observed to make an unsuccessful attempt 

 to pair witli a female on the surface of the water, by climbing 

 on to her back. A Corethra larva once seized a male by his 

 legs and held on for some time until induced to leave go by 

 means of a camel's-hair brush. 



" The small pond or clay-hole in which all theexamples, except 

 one, were taken, contained the usual common aquatic insects in 

 abundance, and the vegetation was also of the usual pond type. 



" The occurrence of this species so late in the season is 

 interesting, as those taken by Lubbock* were obtained in 

 August, and for those recorded by Burton f and Enock % the 

 month is not given." 



Mendelian Heredity in relation to selection.— Prof. 

 PouLTON drew attention to two recent papers by Prof. H. S. 

 Jennings of Baltimore, U.S.A. : (1) " Observed Changes in 

 Hereditary Characters in Eelationto Evolution " (Journ. Wash- 

 ington Acad. Sci., vol. vii, No. 10, May 19, 1917, p. 281), and 

 (2) " Modif^-ing Factors and Multiple Allelomorphs in Relation 

 to the Results of Selection " (American Naturalist, vol. li, 

 May, 1917, p. 301). In (1) the author, referring to the dis- 

 coveries of the French botanist Jordan and to the work of 

 Johannsen on "pure lines," expressed the conclusions to 

 which many naturalists have been led, viz. " that most of 

 the heritable differences observed between closely related 

 organisms— between the members of a given species, for 



* Trans. Linn. Soc, 1863, vol. xxvi, p. 135. 



t Journ. Quekett Micros. Club, 1894-7, vol. vi, ser. II p 148 



X Journ. Quekett Micros. Club, 1894-7, vol. vi, ser. Il' p 275 



