246 F. E. CHIDESTER. 



12. In some species of the Arachnida, particularly the spiders, 

 the females devour the males after copulation. 



13. Moulting on the part of the female before fertilization is 

 not the rule in spiders. It occurs in some genera. 



14. In the ticks, the mouth parts of the male are used to 

 moi>u-n and stimulate the sexual aperture of the female and 

 thus prepare the way for the injection of the spermatophore. 



15. Sexual selection on the part of the female has not been 

 definitely established in the Arthropoda. It appears that the 

 successful male is the one who is strong enough or wary enough 

 to mate with the female, or who has learned soonest by his 

 senses the location of the female. 



1 6. Since chance is a great factor in the presence of the male 

 at the proper time, we must consider that the successful male 

 is the one who first demonstrates his maleness to the female. 

 Though strength is a great factor, opportuneness of proximity 

 appears to be a greater one. 



5. BIBLIOGRAPHY. 



1. Andrews, E. A. 



'95 Conjugation in an American Crayfish. Am. Nat., Vol. 29, pp. 867-873. 



2. Andrews, E. A. 



'04 Breeding Habits of Crayfish. Am. Nat., Vol. 38, pp. 165-206. 



3. Andrews, E. A. 



"10 Conjugation in the Crayfish Cambarus affinis. J. Exp. Zool., Vol. 9, 

 pp. 235-264. 



4. Bell, J. C. 



'06 Reactions of the Crayfish. Harvard Ps. Studies, Vol. 2, pp. 615-644. 



5. Berlese, A. 



'01 Copulation of the House Fly. Rev. Patol. Vegetale, 9, pp. 345-356. 



6. Chidester, F. E. 



'08 Notes on the Daily Life and Food of Cambarus bartonius bartoni. Am. 

 Nat., Vol. 42, pp. 710-716. 



7. Chidester, F. E. 



'n The Biology of the Crayfish. Am. Nat. 

 8 Darwin, C. 



'86 The Descent of Man, and Selection in Relation to Sex. 

 9. Dearborn, G. N. 



'oo Notes on the Individual Psycho- physiology of the Crayfish. Am. J. 

 Physiol., Vol. 3, pp. 404-433. 



10. Emerton, J. H. 



'78 The Structure and Habits of Spiders. Boston. B. \VhiuM.-n. 



11. Fere, C. 



'98 Experiences relatives aux rappmts li<>m<>~<'.\uels chez les hammetons. 

 C. R. Soc. de Biol., T. 5, pp. 549-55 i . 



