444 THE PARASITES OF THE TERMITES. 



It becomes a question as to the claim of Arthromitus being a genus distinct 

 from others previously proposed or established. 



Valentin (Repertorium f. Anatomie, 1836) described a parasitic plant from the 

 large intestine of Blatta orientalis, and from the rectum of Astacus fiuvialis, under 

 the name of Hygrocrocis intestinalis, which would appear to have the same generic 

 character as Arthromitus. Not having access to the original description, I quote 

 the diagnosis as given by M. Ch. Robin (Histoire d. Vegetaux Parasites, 1853): 

 "Fila simplicia, tenuissima, perlonga (articulatal), serpentia, apice recta (monili- 

 formia"? articulis globosis])." This would apply to the plants I have referred to 

 Arthromitus, except in the latter two characters, which, however, are questionable 

 with the author as applied to Hygrocrocis intestinalis. 



Recently I was so fortunate as to catch a large cockroach, Blatta americana, 

 when I proceeded to examine the large intestine with the expectation of finding 

 the same parasitic plant as that discovered by Valentin in the B. orientalis. 

 Surely there it was in abundance, in association with the usual animal parasites, 

 and in it I recognized Arthromitus ; but with sufficient peculiarity, perhaps, to 

 view it as a species distinct from that of our Wood-Julus and Termite. 



The Arthromitus of our cockroach consists of simple filaments, about the same 

 diameter as those of the Julus and Termite. The stouter spore-bearing filaments, 

 as represented in Fig. 35, PI. 52, exhibited more numerous or longer rows of 

 spores which were of the same form as those of Arthromittis cristatus, but were 

 differently disposed. They were transversely situated, often alternating in direc- 

 tion, as seen in the figure. Occasionally they were oblique, but in no instance 

 longitudinal. This diff'erence of position is due to the diff'erence in the propor- 

 tionate size of the articulation in the two forms of Arthromitus ; the joints in that 

 of the cockroach being broader than long, while in A. cristatus the condition is 

 reversed. In the latter the lines of separation of the articulations are commonly 

 most readily detected between the ripe spores, but in the Arthromitus of the 

 cockroach the partitions were better seen in the filament below the spore-bearing 

 portion, as seen in Fig. 35, 



I have assumed that the Arthromitus of the Blatta americana is the same as 

 the Hygrocrocis intestinalis of the Blatta orientalis, though it may be different. 



The genus Hygrocrocis was originally proposed by Agardh (Systema Algarum, 

 1824), on certain fine filamentous plants, growing in chemical solutions, which are 

 rather of the nature of Fungi. Rabenhorst excludes it from his Flora Europsea 

 Algarum, and in a note indicates it as pertaining to the Fungi, 



M. Robin refers the Hygrocrocis intestinalis of Valentin to the genus Lepto- 



