SEVENTH ANNUAL REPORT. 151 
color changes. There seems to be some tonic in the sunshine, 
the soil, and outdoor air. A snake born in August in a wild 
state will, before hibernating-time, grow a third larger than one 
born in captivity, no matter how much food may be provided the 
latter. With this taken into consideration, it is probable that 
captive raised and wild alligators grow at much the same rate per 
year, even though the latter hibernate for a few months of the 
year. 
Although this rapid growth of young crocodilians is in direct 
opposition to the general ideas regarding them, it does not apply 
merely to the young of those reptiles. The large occupants of 
the crocodile pool have increased in length to a surprising degree 
since their arrival at the Park. Our largest Alligator, a ponder- 
ous specimen named Mose, and one of the largest crocodilians 
in captivity, has grown five inches since his arrival at the Park 
in July, 1899. Another fine alligator, now growing with such 
rapidity that it will soon rival ‘““Mose” in dimensions, measures 
at the present time Io feet, 11 inches. During its first year in 
the Park this reptile grew one foot, three inches, measuring at 
the expiration of the year, eight feet, two inches. During the 
second year it increased one foot, one and one-half inches, and 
measured nine feet, three and one-half inches. Last year this 
reptile grew one foot, seven and one-half inches, and now it 
measures within an inch of eleven feet. 
During the rearing of specimens, the curator has enjoyed ad- 
mirable opportunities for noting the transitions in color from the 
young to the mature form. An interesting example of this is 
the coloration of several of the young crotaline snakes. These 
reptiles are born with the tips of the tails, for the length of about 
an inch, of a brilliant sulphur yellow. When food is introduced 
into the cage with these young vipers, they communicate a 
writhing, twisting motion to their tails, causing the latter to 
closely resemble small worms, or maggots. Possibly nature has 
provided these young vipers with this dash of brilliant color to 
attract small birds, lizards, or frogs within their reach, as they 
lie coiled and difficult to discern from the surrounding vegeta- 
tion. This characteristic has been observed in the Copperhead 
Snake (Ancistrodon contortrix), the Water Moccasin (A. pisct- 
vorus), and the Fer-de-Lance (Lacheses lanceolatus). After the 
first year, the yellow of the tail becomes very indistinct, and dur- 
ing the second year it disappears altogether. 
With some of the crotaline snakes, the colors of the young 
are very brilliant, although they exhibit much the same pattern 
