EESEARCHES UPON SPIDEKS. 77 



tember, and a sixth between the end of September and the 

 middle of October. The only difference between the broods 

 was that the last had less silk and fewer eggs than the first. 

 It follows from all this, that the spiders produce many co- 

 coons in a year, generally six ; that females are able to pro- 

 duce fertile eggs without being every time fecundated, and 

 that consequently the number of males may be, as in fact it 

 is, much less than the number of females. 



The discovery that the act of coupling, fecundated 

 through six generations of eggs, the following year, appeared 

 to me, and indeed was, a very important thing. I wished 

 to learn if it was altogether new, and among the many en- 

 tomologists that I have read, I have never seen any mention 

 made of it excepting by Martin Lister, who did not, how- 

 ever, determine either the time or the number of fruitful 

 cocoons formed without coupling. No other writer has a 

 word on the subject. 



In order still further to assure myself, and at the same 

 time to see if the fertilization could be protracted beyond 

 the year, I wished to preserve the same spiders in the win- 

 ter, but three of them perished. Of the seven remaining, 

 I gave one to P. Carlo Giuseppe Campi Somasco, an accom- 

 plished and very accurate naturalist." He kept it so well 

 that between the months of May and June it produced a 

 cocoon twice, from which little spiders were hatched. The 

 spiders in my possession were also found to remain fertile, 

 and those which lived till October remained fertile even to 

 the sixth cocoon. Three had perished in the summer, some 

 after the third, and some after the fifth. The four remain- 

 ing died in the winter. In this way spiders fertilized three 

 years before gave as many as eighteen cocoons without any 

 preceding coupling. I do not know through how many 

 years- the fertilization may be extended ; but it is not im- 



17. To him is due the first thought of the Scelta d'Opuscoli interessanti 

 (collection of interesting pamphlets), commenced in 1775. His poor health 

 did not permit him to cooperate in this work after 1777. But he did not, 

 for this reason, neglect to occupy himself with useful researches. He died 

 in 1799 at the age of 66. — Editor. 



m. It is not stated who this editor was. (Reviser.) 



