No. 373.] LIFE HISTORIES OF CERTAIN SNAKES. 2i 
birth. The food yolk remains attached for some time after 
birth, and zs not entirely absorbed before. 
There is certainly a grave mistake in Dr. H. C. Bumpus’ 
account of Eutenia sirtalis (quoted in the Proceedings of the 
U. S. National Museum, Vol. 15, p. 388), for the genus Eutzenia, 
as stated before, is ovoviviparous, and the young are marked 
just like the old ones, only much more brilliantly. Dr. Bumpus 
must have found the eggs of Bascanton constrictor. 
According to the just-stated observations, the term of gesta- 
tion seems to me definitely defined. At the same time we 
must also give credit to other statements, and the question 
arises, Do snakes copulate twice a year? Observations made 
by me in Europe on Pelias berus, Vipera redii, Tropidonotus 
natrix, and Coronella levis seem to contradict such an assump- 
tion. In all cases, with the exception of Vipera rediz, I have 
seen copulation in captivity, and I found the desire for repro- 
duction to manifest itself in April and May, the young of 
Pelias and Coronella to be born in August and September, 
but the eggs of Tropidonotus to be laid in June and July. I 
placed freshly laid eggs of Tropidonotus natrix and T. persa in 
dunghills, and twenty-three days later I obtained the young 
ones. It is remarkable to notice the tenacity and intent with 
which the males persist in following up the females during the 
time of sexual desire. 
How much I was mistaken in rating the toxic qualities of 
very young venomous snakes is illustrated by the following 
history of the bite of a young Sistrurus miliarius. As stated 
before in this article, I tried the effects of the bite of a young 
water-moccasin and experienced no results worth while men- 
tioning. 
During the noonday hour of Aug. 20, 1894, exactly eight 
days after the birth of the young ground-rattlers, I picked one 
of them up, teased it a little, and presented the first joint of 
the little finger of my right hand fora bite. The little snake 
bit with a vengeance. The momentary sensation resembled 
the sting of a bee; at the same time a lightning-like pain 
seemed to shoot up to the shoulder. A few minutes later 
actual pain extended to the second joint; a slight discoloration 
