50 PSEUDO-ENTOPHYTA, ETC. II. 



CHAPTER III. 

 UPON PSEUDO-ENTOPHYTA, ETC. 







TRUE free or unattached entophyta are comparatively rare, within the aliment- 

 ary canal of animals, because they possess no means of counteracting expulsion 

 with the ordinary contents of the bowels. They may, however, not unfrequently 

 exist where they have a very rapid reproductive power, and are so small that 

 many escape removal at any single expulsive effort of the organ which contains 

 them. 



The Sarcina ventriculi, Goodsir, is an entophyte of the latter character, which 

 being very minute, and rapidly reproduced, is not easily expelled from the stomach 

 under the circumstances in which it is found. 



Vibriones, and closely allied but not spontaneously moving filaments, very fre- 

 quently met with in the intestinal contents of herbivorous animals, are probably 

 true floating or free entophyta, which by their very great minuteness and energetic 

 reproductive power are prevented from entire removal from the alimentary canal. 



In the study of the vegetable parasites of animals, particularly those of the 

 intestinal canal, it is necessary to be careful not to confound the tissues of certain 

 well-known cryptogamic plants, which may serve as food or adhere to the ordinary 

 food of such animals, with true entophyta. Thus fragments of fungi, confervas, 

 lichenes, and the spores of these, used as food, or adhering as foreign matter to food 

 of an ordinary kind, are liable within the intestine to be mistaken for parasites. 



In midwinter, I found beneath an old fence-rail, an individual of Acheta nigra, or 

 large black cricket, within the proventriculus of which were large quantities of what 

 I supposed at the time to be a free, floating entophyte, resembling in general appear- 

 ance the ordinary yeast fungus, Torula, but which I now suspect to be an ergot upon 

 which the animal had fed (PL X. 8). The plant consisted of oblong or oval ve- 

 sicular bodies, apparently thickened at the poles, and filled with a colorless liquid; 

 but this appearance more probably arose from the cells being distended with a single 

 large, transparent, colorless, amorphous globule, which pressed a small existing 

 amount of protoplasma to each end of the cavity. The cells were single, or in rows 

 to eighteen in number. Frequently, a single cell of comparatively large size had 

 an attached pair of cells or rows of cells at one or both ends. Occasionally they 

 were met with, containing one or two small round hyaline, amorphous nuclei. 



The isolated cellules measured from the 7 ^V^ to the T5 V^ of an inch in length 



