132 YEARBOOK, PUBLIC MUSEUM, MILWAUKEE [Vol. III. 



brown phase, but, after shedding, became beautiful ochre-yellow 

 snakes with conspicuous blotches and bands. On these same speci- 

 mens there was discernible a long reddish-brown stripe down the middle 

 of the back, this stripe being especially noticeable after the specimen 

 was killed and skinned. 



On the other hand, Mr. Keitel, whose field experience as a snake 

 hunter should be given weight, affirmed that the bright 3^ellow snakes 

 were the males and the darker ones the females. A dissection and an 

 anatomical examination of all snakes brought to Milwaukee on this 

 occasion failed to support either contention. Specimens that were 

 identical in general color proved to be some male and some female, 

 and out of the total number of sixteen rattlesnakes examined, no par- 

 ticular color phase, such as light or dark, proved a certain index of 

 sex. It appears, therefore, from the evidence at hand, that, as far as 

 Wisconsin rattlesnakes are concerned, the determination of sex by 

 external color is not practicable. 



In respect to the rattle itself we read: "The rattle consists merely 

 of hollow segments of dry, horny skin, one loosely fitting into another. 

 Its growth is from the base of the appendage — the end of the tail 

 proper — hence the terminal joint, ring or segment of the rattle is the 

 oldest one. It is a mistake to imagine the age of a snake may be told 

 by counting each segment of the rattle as a year. Each time the 

 snake sheds its skin a new ring or segment of the rattle is uncovered 

 at the end of the tail; here it is important to explain that rattlesnakes 

 shed from two to three skins a year — that is, during the warm months. 

 At birth the snake has merely a 'button' to represent the future 

 rattle. The first ring uncovered is larger than the button, and each 

 subsequent ring yet larger, until the reptile has attained its full 

 growth, when all of the segments produced are of uniform size. If 

 a snake has a perfect rattle — a button at the tip and successively 

 larger segments — and three joints of the rattle are counted as a year, 

 a fair idea of the snake's age may be acquired. If all the segments 

 are of uniform size, the reptile has lost the segments of its youth — 

 possibly many more of them — through wear or accident, and no idea 

 of the serpent's age can be ascertained except that it is a perfectly 

 mature specimen. The usual number of ' rattles ' is from ten to 

 twelve.""'^ The longest rattle examined by Ditmars consisted of 

 seventeen segments. This rattle was on a large black Timber Rattle- 

 snake and the last three rings already worn and broken were shaken 



"Op. Cit., p. 349. 



