TABLES OF CONSTANTS OF NATURE AND ART. 295 



It is scarcely to be expected that any one individual will, even for 

 a single animal, be able to fill np the whole of the measures pointed 

 out in this short paper, and it would be much to be regretted if this 

 enumeration should from its extent discourage any observer. As, 

 however, some definite portions of this labor, within reach in the 

 course of the next twelvemonth, might perhaps, if accomplished, 

 supply a stimulus to more extensive inquiries, I would propose to 

 those who possess microscopes the determination of the diameter of 

 the globules of the blood of various animals, and to those who are not 

 in the possession of such instruments, or cannot spare the time neces- 

 sary for their use, I would propose the determination of the rate of 

 breathing of various mammalia. The numerous collections of animals 

 now distributed over the continent would render this limited portion 

 of the task a work of comparatively little difiiculty. 



OBSERVATIONS. 



Name. 



1. Length from tip of tail to end of nose. 



2. Height from ground to top of shoulder. 



3. Length of tail. 



4. Length of head. 



5. Greatest breadth of head. 



6. Weight of animal. 



7. Weight of skeleton. 



8. Number of mamma;. 



9. Period of gestation, in da)'s. 



10. Period of blindness after birth. 



IL Period at which they cease sucking. 



12. Period of maturity. 



13. Period of old age. 



14. Number of young at a birth. 



15. Proportion of males to females. 



16 Animal heat ; thermometer centigrade. 



17. Number of pulsations per minute, awake, asleep. 



18. Number of inspirations per minute, awake, asleep. 



19. Number of species known. 



20. Number of toes or claws on fore foot. 



