194 • THE MICHIGAN ACADEMY OF SCIENCE. 



A MICHIGAN BIOLOGICAL SURVEY/ 



H. L. CLARK. 



(Abstract.) 



The need of a biological survey, which will show the present distribu- 

 tion of the plants and animals of the State, is sorely needed, as a basis 

 for further work in both botany and zoology. The Zoological Section of 

 the Academy should appoint a committee to ascertain what has been 

 done and what can be done at once, and to lay plans for the future, to- 

 ward the completion of a complete and accurate catalogue of the fauna 

 of Michigan. 



SNAKE NOTES. 



(Abstract.) 



During the spring of 1903, half a dozen specimens of the short-mouthed 

 snake {Eiitainia hrachy stoma, Cope) were collected about Olivet. As they 

 are the first specimens to be reported since the type taken in Pennsyl- 

 vania was described, a full account of them was published in the ProG. 

 Biol. Soc, Washington, June, 1903. (Two of the Olivet specimens were 

 then exhibited.) 



' One of the largest of our North American snakes is the Bull Snake 

 (Pityophis sayi) which occurs in the western half of the Mississippi 

 valley and is said to reach a length of seventy-five inches. It. is very use- 

 ful in the destruction of small rodents. (Two specimens, eighty-five in- 

 che'* long, from Oklahoma, were then exhibited. They were quite as 

 noticeable for their gentleness and cleanliness as for their size, and were 

 freely handled by the speaker and many persons in the audience.) 



THE VARIABILITY OF SNAKES. 



(Abstract.) 



This investigation was undertaken to determine the differences between 

 the sexes and between adults and young in the common Michigan snakes; 

 to determine what characters are most variable, and which sex is the 

 most variable ; and to decide how great the variability is. 



As the work is still in progress, no i^ositive results can yet be given, 

 but there seems to be evidence to show that in the Natricine snakes 

 (water-snakes) the female is larger than the male and has a shorter tail, 

 fewer urosteges and perhaps fewer gastrosteges. Only a comparatively 

 small number of Colubrine snakes were examined, but in them the males 

 are apparently larger and the sexes are not otherwise notably different. 

 Adult snakes have shorter heads than the young. Male snakes apparently 

 vary more often, but females vary to a much greater extent. Over 900 

 snakes have been examined in twenty-three particulars. 

 H. L. Clark, Ph. D., Professor of Biology, 

 Olivet College, Olivet, Mich, 



