26 PROCEEDINGS OF THE ACADEMY OF [1896. 



Another consideration is, that after all the cell, the individual 

 and the species are the three natural units in biology, without a just 

 conception of which, all reasoning must be futile. The orders, fami- 

 lies, genera and other higher groups do not stand at all on the same 

 plane, being essentially artificial arrangements for convenience in 

 classification. Consequently a student who might be thoroughly 

 acquainted with the higher groups and ignorant of species, would 

 be very little prepared to form just conceptions of the phenomena 

 of life. 



When these ideas dawned upon the writer, he was somewhat dis- 

 concerted to reflect that in the whole range of zoology he possessed 

 an intimate acquaintance with only two series, the slugs in Mollusca 

 and the Coccidse in Insecta. Of the former, which might have been 

 used in zoological studies, there is but one species in New Mexico, 

 and that not found in the neighborhood of the college ; of the lat- 

 ter, the species are more numerous, but very unsuited for the pur- 

 pose required, since they are exceptions to almost every ordinary 

 entomological rule. 



It is perfectly true, that there already exist many very admirable 

 monographs of North American insects of diflfereut groups ; but 

 there are two reasons why even the best of these do not entirely 

 serve our purpose. The first is, that comparatively little collecting 

 has been done in southern New Mexico, so that many of our very 

 common species are even unknown to science, and, therefore, not to 

 be found in the monographs ; the second, that very few of the pub- 

 lished writings contain anything like a careful account of the habits 

 of the species. One of the very first lessons that the student has to 

 learn is that structure is as intimately related to environment, as 

 lock to key, and a work which practically ignores one side of this 

 question cannot be entirely satisfactory. 



The nearest approximation to what is wanted is found among the 

 higher lepidoptera, which are illustrated by such admirable works 

 as those of Scudder and AV. H. Edwards. Yet these insects are not 

 very easily studied by a beginner, except in a superficial way, nor is 

 their classification yet upon a perfectly sound basis. So finally, it 

 was concluded to take up the bees and endeavor to work them up 

 in such a manner that they might be used as desired. They are 

 good typical insects, their principal structural characters are easily 

 observed, their habits are most interesting, and they abound in New 

 Mexico. Moreover, the bee-studies go very nicely hand-in-hand 



