112 JOURNAL OF THE [October, 



I have also consulted the article by Prof. H. L. Osborn, entitled 

 "The Protozoa — a Phyllum of the Animal Kingdom considered 

 Biologically " {American A'lonthly Alicroscopical 'yoitrnal, October, 

 1892), and the presidential address by Mr. Charles F. Cox, pub- 

 lished in the Journal of this Society, January, 1892. I have 

 not had access to the recently published work of Messrs. Frede- 

 rick W. Mills and Julien Deby, "An Introduction to the Study 

 of the Diatomacese " (London and Washington, 1893), so that to 

 this fact must be attributed any lack of acquaintance with the 

 theories which may have been lately proposed. 



Before closing I fain would refer to the use made by certain 

 animals of the Diatomaceas as a part of their food supply, with 

 the view of determining whether the nourishment adapted to car- 

 nivorous animals is made up of microscopic plant protoplasm, 

 either of what is called the ectosarc or endosarc of the Dia- 

 tomacese. The most striking example within my own experience 

 is that source of the Diatomaceae derived from the gizzard or 

 craw-like organ of the mullet of the Gulf bays From such 

 gullets I have secured hundreds of pear-shaped pellets which 

 were literally masses of pure diatoms, and of which I sent many 

 in exchanges, both to foreign countries and also to Mr. C. L. 

 Peticolas, of Richmond, Va., who returned to me at times beau- 

 tiful preparations of the same. I have never found anything else 

 but diatoms and sand grains in these fish gizzards, so this, as far 

 as my experience goes, was the only food supply preyed upon by 

 the mullet. I have also demonstrated that the desiccated ex- 

 crementitious matter left by sea gulls on clusters of pilings in 

 Mobile Bay has been a rich source of marine diatoms, after the 

 undigested particles of fish bones, etc., are dissolved away with 

 acid. As the diet of the sea gulls is principally fish, we can 

 readily account for the presence of diatoms in such a recent 

 source as the living sea gull. The stomach of the oyster some- 

 times yields diatoms, but the green masses found in the stomach 

 are preferably marine algae. The digestive tracts of the sea 

 cucumbers — Holuthurige — have been justlv celebrated for yield- 

 ing immense numbers of marine diatoms. The trepang of the 

 China Sea (which is dried abroad and sold in Mott street, New 

 York, as a Chinese delicacy) is a sun-dried sea cucumber. From 

 several sources we learn that in the Arctic and Antarctic regions 



