294 DE. T. S. COBBOLD ON ENTOZOA IN THE D0&. 



in England. In the young state, and under a different name (P. 

 denticulatum) , it is frequently seen in the human body on the 

 continent. Its mode of introduction into the latter " host " has 

 not been ascertained with certainty ; yet there can be very little 

 doubt that the sneezing of an infested dog in the face of any 

 person would readily transfer the eggs and embryos of the para- 

 site from one host to the other. In like manner, and by the same 

 means, the ova may be cast over and become attached to food, and 

 then be subsequently conveyed to the human stomach. For- 

 tunately its presence in man appears to be unattended with 

 danger ; yet any considerable number of these parasites coidd 

 scarcely fail to produce more or less inconvenience. In Gei'many 

 it seems to be rather abundant ; for Frerichs (no mean authority) 

 states that it is " far more common in the human liver than the 

 echinococcus." In coniBrmation of this statement it has been 

 shown to be present in from 5 to 15 per cent, of post mortem ex- 

 aminations conducted in different Grerman cities. I have myself 

 frequently encountered this parasite in the juvenile state in 

 animals, but not in the human body. The Pentastomes recently 

 described by Dr. Aitken, from the human liver, belong to another 

 and more formidable species. Strictly speaking, these creatures 

 are not true entozoa, although their habits often cause them to be 

 classed as such. Their mode of introduction into the nostrils of 

 the dog is readily accounted for, since the larvae are constantly 

 present in the flesh of herbivorous mammals, and must frequently, 

 during the act of feeding, be brought in immediate contact with 

 the dog's nose. 



19. Oysticercus cellulosce. — Two or three authors (Gurlt, Chabert, 

 and Hartwig) have stated that the common measle of the pork- 

 tapeworm is liable to occur in the dog ; and since we know that 

 it is occasionally found in man, there is no good reason for doubt- 

 ing the correctness of their conclusions. It has been found 

 attached to the membranes of the brain, in the muscles, and in 

 the cavity of the abdomen. If the dog were a thoroughly suit- 

 able "host," this larva would in all likelihood be much more 

 common in the canine bearer than it is at present supposed to be. 

 The possibility of its occurrence and the probability of its having 

 been frequently overlooked should both be considered in reference 

 to future investigations in this direction. 



20. Filaria trispiiiulosa. — This little parasite, once found by 

 Grescheidt in the eye of a dog, is probably only a sexually im- 

 mature form of Ascaris. The specimen, however, was one-third 



