1929] 
Thelytoky in Scleroderma 
121 
CRITICAL DATA UPON THELYTOKY IN 
SCLERODERMA IMMIGRANS. 
By Clyde E. Keeler . 1 
On account of the unusual nature of my results in breed- 
ing Scleroderma immigrans, I thought it well to record the 
evidence pointing toward thelytoky in my specimens. 
(Psyche, Vol. XXXVI, No. 1, pp. 41-44) 
Mr. Bridwell suggested (Psyche, Vol. 36, p. 120) that my 
F3 females might not have remained virgin, due to the fact 
that the early hatching males have been known to chew 
holes into the neighboring cocoons and fertilize their un- 
hatched sisters. The possibility suggested is quite reason- 
able and makes necessary a more detailed explanation of 
the results summarized in Table 1 of my former paper. 
In this table I did not report the contents of all the 
vials individually. The data given under F3 as 1 winged $ , 
1 wingless $ , and 12 wingless $ $ , consisted of insects 
born in five separate vials. 
Vial No. 1 hatched Aug. 14, 1928. A wingless $ , and a 
wingless $ emerged and were removed from the vial. Later 
in the day two wingless $ $ hatched and were kept virgin. 
Vial No. 2 hatched Aug. 27. In this vial was found one 
wingless $ which was kept virgin. 
Vial No. 3 hatched Aug. 29. This vial contained four 
wingless $ $ . They were kept virgin. 
Vial No. 4 hatched Sept. 16. In this vial there hatched a 
single wingless $ , which was kept virgin. 
Vial No. 5 hatched Sept. 16. In this vial were found 1 
winged $ and 3 winged $ $ . These were mated together. 
iResearch Fellow, Harvard Medical School. 
