RESEARCHES UPON SPIDERS. 73 



sexual organ; and I saw, being conveniently situated 

 for observing, the palp, from which a horny white body 

 of changing figure was drawn out, penetrate many times ; 

 and I saw also, the spider use alternately, now one and now 

 another of the palpi. But I saw also with surprise and in- 

 dignation that, the work hardly finished, the male not being 

 able to fly on account of the confinement, the female envel- 

 oped him in her threads and, having thus deprived him of every 

 means of defence, devoured him. Perhaps overpowering 

 hunger compelled her to it, but the act was very ferocious.^^ 

 Whatever were the results, this observation gave me an op- 

 portunity of seeing the sexual organs of both spiders. The 

 generating palp of the male appears through the microscope 

 as in fig. 2 at a and at h. The (anterior ?) extremity of 

 the abdomen of the female is drawn in two aspects in fig. 

 3, the upper side at a and the under side at h in the form of 

 an elongated tube, a form which I have observed in some 

 flies and in a few other insects, which, while it aids to a more 

 sure fertilization, serves also for conveniently placing the 

 eggs. 



Sexual organs, not precisely similar, but analogous to 

 these described, I have observed in other species of spiders, 

 which I will here describe briefly, as I have many times ob- 

 served them, giving also exact drawings from life. Fig. 4 

 represents the nmrirwrata spider (Aranea marmorea h.J, as 

 useful as the diadema spider, whose habits it shares to some 

 extent. The cocoon is whitish and is found under planks 

 and in garden vases. The feminine part is represented by 

 fig. 5, and the male by fig 6, where it is shown drawn out 

 by pressure : a is the sheath which encloses and protects it ; 

 from the opening b issues a tuft of hair, the use of which 

 I know not, and many hairs are seen around the sexual 

 parts of both. Figures 7 and 8 represent the back and 

 abdomen of a pretty female spider (Aranea speciosa di Pallas) 

 which frequents hedges. It spins a web near the ground, 



13. But I ought to say that I have not found other spiders so ferocious. 

 The Aranea cucurhitina remained with his companion in a little box the en- 

 tire season, and if I gave them a fly, instead of quarrelling over it, they ate 

 it together peaceably. 



COMMUNICATIONS ESSEX INSTITUTE, VOL. V. 11. JULY 31, 1866. 



