ZOOLOGICAL SOCIETY BULLETIN. 



655 



the lonp; train of puzzles that confront scientific 

 workers, comes the decision that the appalling 

 spread and the great difficulty of eradicating 

 the deadly bubonic plague, are evils traced di- 

 rectly to that mean-tempered slinking creature 

 that must be rated as one of the greatest pests 

 of civilization. The decision is, that the rat is 

 susceptible to plague infection, and is infested 

 with fleas that are always quite willing to leave 

 the original host, when the blood of the latter 

 is well tenanted by the formidable bacilli, and 

 add variety to their sanguinary instinct b}^ biting 

 members of the human family. The proboscis 

 of an infected flea hypodermically transfers the 

 plague culture to the human. Numerous reput- 

 able writers have emphatically explained that 

 the multiplication of the common rat menaces 

 the world, and, if left unchecked, would mean 

 the annihilation of human life. And in the face 

 of this, it appears unfortunate enough that many 

 common enemies of the rat are being persistently 

 persecuted and exterminated. Among these are 

 the snakes, hawks and owls. The reptiles are 

 of especial importance owing to their prowling 

 and subterraneous habits. They destroy the en- 

 tire litters of j'oung rodents in the nests, and a 

 single snake may perform the work of a dozen 

 hawks. 



While the ravages of the common rat may be 

 rated as most formidable among the North 

 American members of the Mtiridce, the rice-field 

 rat, the cotton rat and the wood rats are other 

 rodents that Nature must keep in constant check 

 for the good of the great general scheme of life. 

 This also relates to the innumerable species of 

 mice. The rats and mice are well represented 

 in the collection to which this article relates, as 

 well as those curious gnawing animals known as 

 the pocket mice, {Hderomyidce) , txnA those ugly, 

 strong-jawed creatures known as the pouched 

 rats, or pocket gophers, Family Geomyidce. 



RODENT DESTROYERS. 



In tiers of cages beneath those containing the 

 rodents, we are now arranging the series of eco- 

 nomically important serpents, the greater num- 

 ber of these North American species, for the 

 opening of this displaj'. As enemies of the 

 common rat, however, which dangerous pest has 



extended its domain to all jiarts of the world, 

 will be shown a series of rat-eating serpents 

 from various widely separated parts of the 

 globe. 



Among the North American serpents, one of 

 the most useful species is the indigo snake, or 

 gopher snake, {Spilotes corals couperi), a spe- 

 cies confined to the southeastern portion of this 

 country. It is a handsome, glossj', blue-black 

 reptile, with a dash of red on the throat, attains 

 a length of nine feet, and prefers rodents over 

 all other prey. This fine and useful reptile 

 should be protected by the state laws of South 

 Carolina, Georgia, Florida, Alabama and Texas, 

 for several species of rats, besides the omnipres- 

 ent domestic species, abound in those states. 

 The species ranges from Brazil northward 

 through Central America, Mexico, thence into 

 the United States ; the range in the latter fol- 

 lowing the east coastal region. In Central 

 America the valuable habits of this rodent-de- 

 stroying reptile are well appreciated and the 

 species is protected. 



In the western L^nited States are several large 

 and powerful serpents belonging to the genus 

 Pituophis. The bull snake, — also called the 

 yellow gopher snake, (P. sayt), is the most 

 widely distributed. It attains a length of eight 

 feet and its color is yellow, with a chain of 

 brownish dorsal saddles. It ranges over a great 

 part of the country inhabited by the grain-de- 

 stroying ground squirrels, where, together with 

 hawks and several species of the carnivorous 

 small mammals, it wages constant warfare 

 against the small gnawing animals. The im- 

 portance of the work performed by this serpent 

 cannot be fully appreciated without due realiza- 

 tion of the reptile's habit of entering the deep 

 burrows of the rodents and destroying whole lit- 

 ters of young in the course of a meal. 



Among the serpents of marked economic im- 

 portance inhabiting the United States east of 

 the Mississippi and northward into the New 

 England States, is the familiar blacksnake, or 

 racer, (Zamenis constrictor), which is a busy 

 destroyer of mice. The "milk" snake, {Ophi- 

 bolus doliatus triangulus), sometimes called the 

 checkered "adder," — is of great value to the 



