68 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



of the nesting species of Orbweavers does the same rule obtain, thus fol- 

 lowing the line of similar mating habit? 



With Epeira trifolium the males observed by me are very much smaller 

 than the females. The disproportion is nearly as great as between the 

 male and female of Argiope. In the case of Epeira insularis the male is 

 smaller than the female, but the disproportion is not great. The male of 

 Epeira domiciliorum is not greatly inferior to the female. The male of 

 Epeira cinerea is smaller in abdomen, but in the size of the cephalothorax 

 and mouth parts is about equal, and the legs, if anything, are 

 ?l° more powerful. So far as our American species throw light 



Disparity upon the question, it would seem that the Orbweavers who per- 

 sistently dwell within tents, show no very marked disparity of 

 size between the sexes. This is the rule, with occasional exceptions. Among 

 British spiders, as described by Blackwall, the case is as follows : In Epeira 

 quadrata the male is about one-half the size of the female ; the female of 

 Epeira apoclisa is about one-third longer than the male.^ The i^roportions 

 are nearly tlie same as those prevailing between the sexes of American 

 nesting species; but there is apparently a greater tendency in the former 

 than the latter toward diminished size of the males. On the whole, it can 

 hardly be inferred that the facts among Orbweavers indicate that equality 

 of size results from contact of male with female without the mediation of 

 a snare. 



It has already been intimated that, ordinarily, where the sexes habitu- 

 ally come into direct contact, by reason of tlieir natural habit, the dispar- 

 ity in size between them is less noticeable. Even among species 

 Sexual of h^q Sedentary tribes, such as the Tubeweavers, where union 

 izem j^^g ^^^ occur during suspension upon the web, this rule ob- 

 weavers tains. For example, the male of Agalena nsevia is quite as 

 large and powerful as the female. In the case of the remark- 

 able Water spider of Europe, Argyroneta aquatica, the male is even larger 

 than the female. There is, perhaps, some relation between this fact and 

 the necessity which seems to be compelled by the element in which the 

 life of the species is spent, and which appears to preclude anytliing like 

 cautious approach. The male Argyroneta must necessarily adopt for his 

 motto the Virgilian sentiment "Fit via vi" in his approach to his lady's 

 domicile. It thus falls out that the superiority of size proves to be a con- 

 siderable advantage to him. 



Among Tubeweavers, generally, there exists no very marked disparity 

 of size. With the immense creatures popularly known as Tarantula, the 

 Mygalidae, the male is certainly somewhat smaller than the female, but the 

 difference is not sufficient, as far as my observation extends, to make any 

 great disproportion in vigor. In fact, in this and in all other cases, it 



• Spi. Gt. Brit, and Ir., plate xxii., Figs. 236, 237. 



