160 RECORDS 



thus be imprisoned in the cocoon ; for the densely woven 

 (normally lower) end of the cocoon is probably impenetrable to 

 the issuing moth. A series of experiments are now being tried 

 to determine whether the peculiar coloration of male moths in 

 dimorphic species is due to sexual selection on the part of the 

 female. In the case of Callosamia pronietJiea there appears to 

 be none, for males are accepted even when female wings are 

 pasted upon them, or when their wings or scales are entirely 

 removed. In the case of 0. dispar, however, there is a decided 

 selection against males whose wings have been cut off; 57 per 

 cent, of the perfect males succeed in mating with the females, 

 whereas only 19 per cent, of the wingless males are successful. 

 The peculiar coloration of the males in these cases has probably 

 not been brought about through the agency of sexual selection 

 on the part of the female, but may be due to race tendency 

 toward variation in a definite direction unchecked by natural 

 selection. 



This paper was discussed by Professors Dean, Crampton, and 

 others. 



Dr. Linville, in his paper, showed that the investigation of 

 the habits of AmpJiitrite oniata and Diopatra ciiprea brings to 

 light many interesting adaptations. The first named lives in 

 U-shaped tubes in sand and mud, access to water and food be- 

 ing possible at either end. Additions to the tube are made at 

 the ends by the tentacles, which are continually drawing in 

 small masses of sand. However, there is every indication that 

 in this animal, where no occasion exists for a protecting tube, 

 continued tube-building is merely incidental to food getting. 

 Food is brought to the mouth, which is always concealed, in 

 the masses of sand and in water currents created by the inward 

 lashing cilia which thickly covers the tentacles. 



Diopatra lives in a tough, mucus-covered lined tube, with 

 its deeper end bare, and serving as an anchor, while its outer 

 free end is studded with bits of shell and gravel. The animal 

 may expose its anterior portion while searching for food and 

 for suitable material to add to its tube. Observations made in 

 the laboratory indicate that the animal chooses these materials 



