No. 373-] LIFE HISTORIES OF CERTAIN SNAKES. 19. 
the exact counterpart of their mother in color and markings, 
the ground color, however, much lighter, and the head being 
much more obtuse. Their length was five and one-half inches 
by a trifle less than one-fourth of an inch. 
According to the condition of the weather and temperature, 
it is hardly possible that the snakes left their winter quarters 
before the beginning of March; mating must have taken place 
soon after, and, supposing it to have occurred about the middle 
of March, it will then determine the term of gestation to five 
months, or possibly a trifle over. 
While on Avery’s Island I captured, on April 1, two large 
water-moccasins. I kept the pair isolated from other snakes, 
but exactly thirteen days (August 25) after the birth of the 
ground-rattlers I came also in possession of eight young water- 
moccasins. 
The same conditions as to temperature and the appearance 
of the snakes after hibernation prevailed in this case, and we 
find the term again to be five months and possibly a few days 
more. 
In regard to the quotation of the notes on the pairing, etc., 
of Agkistrodon piscivorus, as observed by Effeldt in the Berlin 
Zoological Garden,! the period of gestation is considerably over 
five months. The dates, however, appear to have been noted 
with accuracy, and the excess of days in the period, if compared 
with my own notes, may be due to the climatic conditions under 
which the occurrence took place; but the statement of the size 
of the young at birth, as well as the color and markings, I 
believe to be unquestionably wrong. Our largest Crotalidze 
never bring forth young of the length of ten and two-fifth 
inches, much less a water-moccasin. 
On April 12, 1895, a negro came to me with an ordinary 
bird trap-cage. In it he had two magnificent copperheads, 
which he said he had caught on the previous evening in a cane- 
brake in the act of copulation. I purchased them and devoted 
considerable time to their care. Both of them accepted food 
very readily, and after awhile became gentler and more tractable, 
a trait which seems to me very much pronounced in copperheads, 
1 Report of U. S. National Museum, 1893, pp. 409, 410. 
