EODENTIA 317 



condition of the cat's tapeworm being familiarly known as 

 Cysticercusfasciolaris. This sexually -immature tapeworm infests 

 many other rodents, especially the voles (Arvicolidce) . In 

 regard to Trichina it must not be forgotten that their presence 

 in rats is not uncommon in some parts of Europe; and this 

 circumstance may explain the recurrence of trichinosis (first in 

 hogs and then in man) in certain outlying districts. Only in 

 this way' can the Cumberland outbreak in this country be 

 accounted for. Here I cannot dwell upon the subject, but in 

 this connection I may observe that Bakody has in a very con- 

 vincing manner described a new variety or species of Trichina, 

 found by him infesting the walls of the stomach and intestine 

 of rats. In the first instance he detected the worm in associa- 

 tion with the ordinary T. spiralis, but afterwards separately. 

 He also obtained it in fowls. The species should be called 

 Trichina Bakodyii. Possibly the nematodes observed by Colin 

 in 1863 also refer to this worm. They occupied tubercles in 

 the liver of a rat. In regard to the beavers (Castorida) it 

 appears that they harbor many species of round worms, and 

 also several flukes, but they do not appear to have been very 

 much studied. In Morgan's work on the American beaver 

 there is a notice in which it is stated that Dr Ely found a very 

 fine filamentous worm 40"' in length. This does not seem to 

 correspond with Ascaris castoris (Rud.). He also speaks of 

 large numbers of a slender white worm, 3" to 5" in length, 

 found in the peritoneal cavity, and referable to the genus 

 Filaria. This cannot be confounded with Trichocephalus 

 castori (Bud.). Moreover, he describes a strongyle (Sclero- 

 stoma) as infesting the colon, and especially the caecum. These 

 all appear to be new to science. The Fasciola hepatica is 

 occasionally found in the liver, but the most common helminth 

 of beavers is Amphistoma subtriquetrum. Specimens of this 

 worm may be seen in the British and Hunterian Museums. 

 As regards the porcupines (Hystricidce) I have already men- 

 tioned the occurrence of a tapeworm in the common species. 

 The larval Pentastoma denticulatum has been found by Otto 

 attached to the surface of the lungs, and R-edi, about two cen- 

 turies back, noticed small nematodes lodged in tubercles of the 

 oesophagus. The late C. M. Diesing obtained Trichocephalus 

 affinis from the intestines. So far as I am aware, little or 

 nothing has been said respecting the helminths of the Octo- 

 dontida, Chinchillida, and Cavidce. Like other European 



