ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 5 i 3 



8. Arachnida. 



Courtship of Spiders.* — T. H. Montgomery discusses the signifi- 

 cance of the courtship and the secondary sexual characters of Araneads. 

 After describing the general mating relations, the numerical proportions 

 of the sexes, the relative time of maturity, and the senses employed in 

 sexual recognition and stimulation, the author gives an account of the 

 phenomena of courtship in " Snarers " and " Hunters," taken partly 

 from his own observations on the Lycosids, partly from the literature of 

 the subject. 



He finds that, in the male, the chief psychical condition is sexual 

 desire resulting from a physiological state due to internal secretions at 

 the time of maturity. But with this is associated an inhibiting factor, 

 the male's fear of the female. One of the most general motions made 

 by the male is the raising of the forelegs towards the female, and this 

 is but a modification of the spider's general attitude of defence — a 

 motion exhibited by both sexes when strongly disturbed. Similar ex- 

 planations are suggested in regard to the waving of the palpi, which 

 may follow any excitement, and the lateral flexion of the abdomen, 

 which may be due to the tension of a silken thread secreted when the 

 spider, in his movements, touches the ground with his spinnerets. 



Montgomery concludes that the male spider, in visual courtship, is 

 not actuated by a conscious effort to exhibit his peculiar beauties, and 

 that the female does not select males by anesthetic sense. Courtship 

 by the male results simply because fear is mingled with his desire ; and 

 probably the female will accept the first male who courts her and makes 

 himself recognized as a male at the time when she is physiologically 

 desirous. Sexual selection, in Darwin's sense, has probably played no 

 part in the evolution of the secondary sexual characters of spiders. 

 The nature and use of secondary sexual characters are next discussed. 

 They are classified as : weapons employed by males in their combats 

 with one another ; characters used for sexual recognition and sexual 

 stimulation ; characters of more immediate value in assuring approxima- 

 tion of the sexes and copulation ; characters of value in provision for 

 and nurture of the progeny ; characters due to habitudinal differences 

 of the sexes ; characters of value in protecting a particular sex against 

 other species. Analysis of these six categories of secondary sexual 

 characters shows that, as far as spiders are concerned, natural selection 

 alone is sufficient to explain the regulation of the phenomena. At the 

 same time, these phenomena would seem to have a manifold origin, as 

 they certainly fulfil very different uses. 



New Hydrachnids.f — Edward Schechtel describes Limnesia polonica 

 sp. n., and the hitherto unknown female of Arrenurus nodosus Koen., 

 both from Galicia. 



f' Crustacea. 



Sympathetic Nervous System of Crustacea.! — Jerzy Stanislaw 

 Alexandrowicz has studied this in rock lobster (PaUnurus), crayfish 



* Amer. Nat., xliv. (1910) pp. 151-77. 



f Bull. Internat. Acad. Sci. Gracovie, 1910, pp. 92-4 (1 pi.). 



X Jenaisch. Zeitschv. Naturw., xlv. (1909) pp. 395-444 (5 pis. and 8 figs.) 



