30 A FLORA WITHIN ANIMALS. IL 



2. Eccrina moniliibrmis, Leidy. 



Proo. Acad. Nat. Sci^, v., 35. 



Thallus colorless or ambreous^ transparent, growing in a double or triple spiral. 

 Pedicle short. Principal cell cylindrical. Secondary cells in various stages of deve- 

 lopment, from 20 to 50 in number, globular when fully formed. 



Whole length, from 1 to IJ lines. Breadth of principal cell y-^Tj- of an inch. 

 Diameter of secondary cells, from the ^^V'S" ^^ ^^^ tsVtt ^^ ^^ inch. 



Habitation. Parasitic, growing from the mucous membrane of the intestinal 

 canal of Polydesmus granulatus. 



§ 6. History, Structure, etc. of Eccrina. 



The genus Eccrina I have not had an opportunity of studying with as much 

 care as Enterobryus, simply because the animals in which it is parasitic are 

 not so abundant in the neighborhood of Philadelphia as the species of Julus. 

 When I first discovered Eccrina moniliformis, I took notes of its appearance, but 

 deferred figuring it until a more favorable opportunity, which, however, has not 

 yet arrived ; for I have since not been able to find any other than the young of 

 Polydesmus granulatus, in which the entophyte, not constantly existing, does not 

 present the fully developed condition. 



To my friend. Professor Baird, then of Carlisle, Pennsylvania, now of the Smith- 

 sonian Institution, Washington, I am indebted for numerous individuals of Poly- 

 desmus virginiensis, from which I obtained materials for figures and full descriptions 

 of Eccrina longa. 



This species is remarkable on account of its very great relative length, not only 

 to the other entophytes described, but also to the animal in which it is parasitic. 



•The principal cell in both species of Eccrina is almost uniformly cylindrical 

 throughout, and in Eccrina longa, at its lower part, makes a long sigmoid flexure, 

 or single spiral turn, as in Enterobryus elegans, while in Eccrina monilifcyrmis, in 

 union with its secondary cells, it usually makes a double or triple spiral, as in 

 Enterobryus spiralis. 



The breadth of Eccrina longa is not so uniform as that of Eccrina moniliformis, or 

 the different species of Enterobryus, nor does it usually correspond to the length. 

 Thus, I have observed filaments 4 lines in length, the y-^-^ of an inch in diameter; 

 filaments of 5 lines, the -g- j^ of an inch ; a few of 3 lines, only the ^ ^-^ of an inch, &c. 



Eccrina is the most remarkable of the entophyta which I have discovered, be- 

 cause a full-grown individual exhibits at one view the process of multiplication of 

 cells by division in the most gradual state of progression. 



1. Of the Principal and Secondary Cells. — (PI. V. 1-6.) The description of these 

 two kinds of cells must be given together, as the contents in the distal extremity 

 of the one pass gradually into the construction of the other. 



The cell-contents consist of the same materials and in the same varying character 

 as in Enterobryus, except in full-grown individuals, in which, at the distal extremity, 



