158 



ZOOLOGICAL SOCIETY BULLETIN 



f 



PHOTOGRAPH 



COMMON BOA, 

 One of the most brilliantly colored species of the Boidae. 



Boinae of this family, are not, as is popularly sup- 

 posed, confined to the New World. The majority 

 of the species, and in fact all the larger ones, in- 

 habit tropical South America, southern Mexico, 

 Central America and the West Indies. One small 

 species occurs in the extreme western portion of 

 the United States, as far north as Oregon. The 

 genus Eryx, however, composed of small bur- 

 rowing forms, inhabits Africa, southern Europe 

 and Asia. Two fine species belonging to the 

 genus Boa are found in Madagascar; and several 

 other genera are represented in the Old World. 

 In the New World, the largest of the boas is the 

 Anaconda, or Water Boa, of tropical South Amer- 

 ica, a species alleged to attain a length of twenty- 

 five feet or more, but specimens of such dimensions 

 appear to be so exceedingly rare that they never 

 find their way into captivity. Two fine specimens 

 of this aquatic snake are on exhibition in the 

 Reptile House. The largest specimen, measuring 

 sixteen feet in length, recently gave birth to thirty- 

 four young. The young snakes are being care- 

 fully fed, and it is anticipated that the majority 

 of them may be reared. At time of birth they 

 were twenty-seven inches long, and of much the 

 same coloration as the parent. Like the adult, 

 they are very vicious, and resent handhng. Quick- 

 ly twisting from side to side, they endeavor to snaj) 

 at the hands of their keeper. Most of their time 

 is spent in a large tank, where they swim slowl}' 



or mass themselves in a corner with only their 

 snouts above the water. 



The birth of these little snakes illustrates a 

 characteristic predominant among the boas, the 

 majority or possibly all of which are viviparous, 

 bringing forth their young alive. The pythons, 

 on the contrary, lay eggs, over and about which 

 they coil, and so remain until they hatch, after 

 some six or eight weeks' time. The writer has 

 several records which tend to demonstrate that 

 the progeny of all the Boidae are very numerous. 

 One of these relates to a large specimen of the 

 Common Boa {Boa constrictor), whicli gave birth 

 to sixty-four living young. Another is a note 

 from Antwerp, where an Anaconda, fifteen and 

 a half feet in length, gave birth to thirty-seven 

 young. Various records show that the pythons 

 deposit from fifty to one hundred eggs. A twenty- 

 foot Regal Python in the Reptile House deposited 

 sixty eggs, about which she coiled, and from her 

 position fought oft" all intrusion. Her eft"orts at 

 incubation proved of no avail, however, as the 

 eggs were infertile. 



The growth of the young anacondas in the Rep- 

 tile House will be noted with great interest. Cap- 

 tive-born snakes usually feed readily, and in con- 

 sequence grow rapidly. It is hoped, therefore, 

 that there will be an opportunity to ascertain the 

 limit of size attained by this species. Although 

 popular supposition says twenty-five feet, we 



