﻿FIELD AND FOREST. 79 



opportunity of referring to one or two other matters. In the " Mam- 

 mals and Winter Birds of East Florida," I freely confess to having too 

 hastily formed conclusions "regarding the relationship of certain con- 

 generic forms " in several instances among the Fakonidce, and in one 

 or two other groups, (Bucephala and perhaps in Centurus,) and that 

 I made a mistake in respect to Pipilo macronyx, but the question of 

 whether certain forms referred to are " species ' ' or merely " geographi- 

 cal races " does not seriously affect the points then under discussion. 

 Probably there is still a difference of opinion between Mr. R. and my- 

 self, respecting several of the components of the groups in question. 

 The case of Peuccea " Cassmi," however, is somewhat different, as is 

 shown by the following quotation from " North American Birds," (Vol. 

 II, p. 43,) published two years after the occurrence of the alleged gross 

 blunder. In the above-named work it is stated that " the general ac- 

 ceptance of the name Cassmi has been that of a term designating a va- 

 riety of the common species," — which is just the sense in which I used 

 it, the discovery of the impropriety of which had not, at that time, been 

 made public. 



Mr. Ridgway, perhaps I may be allowed to add, has had to correct 

 his own "hasty conclusions," or has had them pointed out by others, 

 quite too often for such criticism to come with very good grace from 

 his pen. 



J. A. Allen. 



Vegetable and Animal Cellulose. 



In each of the monthly reports of the Department of Agriculture for 

 July, 1875, an d May and June, 1876, appears an article on the sub- 

 ject of cellulose, both A'egetable and animal. The first article relates 

 mostly to the discoveries and observations of the scientists of Europe 

 on animal cellulose, and the second to experiments based on them, to- 

 gether with others made by myself with their results, being really a 

 continuation of the original observations of Virchow. Any person who 

 has given this subject full consideration will comprehend the scope and 

 tendency of these investigations. If it can be shown, to a demonstra^- 

 tion, that vegetable cellulose is a constant constituent in the organs 

 and blood of the higher animals, including man, we establish the fact 



