COMPARATIVE VIEWS OF VARIOUS MATING HABITS. 



must be remembered that the abdomen of the male is always, and neces- 

 sarily, by reason of difference in organization, much smaller than that of the 



female, which gives him, to the current observer, the appearance 

 Anatomy °^ being less in general size. But the organs of offense and 



defense are not situated in the abdomen. The legs and mouth 

 parts of the male, including the cephalothorax, are often equal or superior 

 in size to those of the female, even when lie seems at a casual glance to 

 be much smaller by reason of difference in size of the abdomen. 



Among the AVandering tribes the same rule holds good. The Attoi'ds 

 show a substantial equality in size between the two sexes, there being an 



average difference of aljout one-sixth in favor of the female, 

 derers ^^^^' ^^^^^ difference in size does not necessarily imply a difference 



in physical vigor. It must also be remembered that at the mat- 

 ing period the sexual excitement of the male imparts an abnormal degree 

 of strength, which helps greatly to overcome any disparity in physical or- 

 ganism which may exist. The Lycosids follow the same rule of substan- 

 tial equality in size, with a slight difference in favor of the female. 



In the case of the Laterigrades the rule holds good, as an examination 

 of the superb plates of Blackwall's "British Spiders" (Plates IV and V), 

 will show. There are some remarkable exceptions, for which I am not 

 able to account. With a few Thomisoi'ds there is said to exist the same 

 immense disparity in size that has already been noted between the sexes 

 of the Orb weaving Nephila and Argiope.^ 



IV. 



The numerical proportion of the two sexes is a matter of great interest, 

 not only in itself, but in its bearing upon certain theories, especially relat- 

 ing to development. The facts are so insufficient, and at many 

 Numeri- points so conflicting, that it is a difficult matter to arrive at any- 



,. thing like a settled conclusion, 



portion nT T^ 



of Sexes. ^'^- Eugene Simon remarks that in the genera where the in- 

 equality between the sexes is slightest the number of males ap- 

 pears to be equal to that of the females, since at the period of amour Orb- 

 weavers having this characteristic regularly come together in pairs. But 

 in the genera where there is a great disproportion of size the number of 

 males is much more considerable, since it is not unusual to see four or five 

 individuals of the sex courting one female. These little males mature first, 

 but the duration of their life appears very short, for after the period of re- 

 production they completely disappear. They do not construct a proper 

 web, but keep in the neighborhood of those woven by the female, watching 

 for the propitious moment for union. - 



' Cambridge, Art. Arachnida, Brit. Encyc. 

 ■ ^ Les Arachiiides de France, I., page 20. 



