30 



A FLORA WITHIN ANIMALS. II. 



3. Of the Mode of Attachment of the ThaU us. —Although, the attachment of 

 Arthromiius is very firm and tenacious, yet the thaUus possesses no pedicle like 

 that of Enlcrohrijus And Eccrina, but grows from granular bodies resembling those 

 upon which the algoid filaments of the human teeth, and those of other animals, 



are based. 



The granules of attachment, from which a few filaments start, are often single 

 or isolated ; but usually there is an aggregation of several granules, from which 

 grow more or less dense bunches of the plant (3, e; 14, a; VIII. 5). The granules 

 adhere to their basis of attachment as if cemented. They measure from the 20000 

 to the lijj of an inch in diameter; usually appear globular in form, and are 

 amorphous and amljer-colored, and refract light as highly as oil-globules. 



4. Of the Particular Locality and Mode of Qroioth. — Arthrornitus may be found 

 in at least 90 per cent, of cases, within the ventriculus of Jidus marginatus, rang- 

 ing from single isolated filaments to very dense bunches. It grows, in company 

 with Enterohjrus clegans, from the mucous membrane, especially near the com- 

 mencement of the organ. When in bunches, or tufts, the filaments spread or radiate 

 from their central granules of attachment, hke a dense tassel held upwards. Oc- 

 casionally, the bunches are found closely twisted, with their filaments intertwined 

 and plaited, forming columns, from the 3 oVcr to the j2Vo' of fin inch in diameter, 

 spreading at the summit. 



Arthrornitus is frequently found growing upon Ascaris infecta, Slreptostomum agile, 

 and Thelastomum attenuatum, upon any part of the exterior surface, but most usually 

 from the lips of the anal and generative apertures, or the interspaces of the annuli 

 of the body; these, apparently, being the most favorable resting-places for the 

 sporuli from which the filaments are developed. 



It is also frecpiently found growing in great profusion upon Enterobryus eJegans, 

 often in dense bunches, covering its summit (PI. III. 12), or in a number of con- 

 centric circles on any part of its length, or radiating from particular points (PL VI. 

 1, h). A favorite locality for its growth, upon this species of Enterobryus, is the 

 basis of attachment of the pedicle of the latter, or the junction of this with the 

 primary cell. The youngest individuals of Enterobryus are sometimes so com- 

 pletely covered with Arthromiius as to be entirely obscured or hidden from view 

 (PI. IV. 16, c). 



As before mentioned, Arthrornitus reaches its highest degree of development in 

 the large intestine of Julus marginatus; a curious fact, when we recollect that 

 Enterobryus elegans, although growing here in greater profusion than in the ventri- 

 culus, never advances to the formation of secondary cells. In the same relation 

 to quantity as we find Enterobryus, with its state of development in the two cavities 

 mentioned, so we also find that Arthromiius, with its greater degree of perfection 

 ni the large intestine, does not grow in dense bunches, as in the ventriculus, but in 

 a very small number of filaments associated together, frequently in pairs ; two, 

 four, or eight, often single, very rarely more than eight together. 



I have never observed Arthromiius to be parasitic upon the entozoa or Enterobryus, 

 within the large intestine of Jiohis marginatus. Arthromiius is found within the 

 ventriculus of Pohjdesmus virginiensis, but not in the profusion in which it occurs in 



