30 



A FLORA WITHIN AiNIMALS. • H. 



S. Eccrina inonilifos'SMss, Leidy. 



Proc. Aciid. Nat. Sci., v., 35. 



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

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

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



Whole length, from 1 to 1* lines. Breadth of principal cell j^Vo of an inch. 

 Diameter of secondary cells, from the y^Vs *« *^^ isVo of ^^ i"ch. 



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

 canal of Polydesmiis granidatus. 



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



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

 care as Enterohnjus, simply because the animals in which it is i^arasitic 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 fiivorable opportunity, which, however, has not 

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

 Polydesmus granidatvs, 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 wdiich 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 entophj'tes 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 fiexure, 

 or single spiral turn, as in Enterohryus elegaiis, while in Eccri7ia moniliformis, in 

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

 Enterohryus spircdis. 



The breadth oi Eccrina longa is not so uniform as that o£ Eccrina monUiformis, or 

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

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

 filaments of 5 lines, the ^4^ of an inch ; a few of 3 lines, only the ^^Vo 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 die PrincijHd and Secondary Cells.— (PL 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 Enterohryus, except in full-grown individuals, in which, at the distal extremity, 



