Linton. — Seasonal Distribution of Parasites 51 



cured meat in the salt cod, it may be easily understood 

 that there can be no such thing as infection following 

 their accidental introduction into the human stomach 

 along with the food. If there should chance to be one 

 who prefers his fresh-fish rare or underdone, I feel rea- 

 sonably secure, in the absence of experimental proof, that 

 his digestive juices will furnish unkindly cultures for 

 such forms as Ascaris clavata, adult in the alimentary 

 canal of the cod, and immature and encysted in the body 

 cavity of a large number of fish. 



Upon looking over my records I note immature and en- 

 cysted nematodes in small numbers in the large sculpin 

 (Acanthocottus octodecimspinosus) in all the months in 

 which examinations were made, viz., January, February, 

 March, April, May, July, October, November and Decem- 

 ber. So far as my records go, therefore, there does not 

 seem to be any seasonal control over the source of infec- 

 tion in this case. 



My records for the cod (Gadus callarius) are made 

 up, almost entirely from collections made by Mr. Vinal 

 Edwards. They show that examinations were made in 

 January, May, August, October, November and Decem- 

 ber. Again the record shows adult and young ascarids 

 appearing in each of these months, indicating that there 

 is no particular season when these worms are acquired. 

 When it is recalled that the adult ascarid in the intestine 

 of the cod was an encysted ascarid in the body cavity of 

 another host that was eaten by the cod, where it had lain 

 for months or even years, since one often finds them sur- 

 rounded by considerable accumulations of degenerate tis- 

 sue, it can easily be seen that the seasons can have nc 

 effect on the occurrence of such parasites so long as the 

 final and secondary host are associated throughout the 

 year. In cases of migrations, which do not accompany 

 migrations of food, conditions might arise which would 

 occasion a periodicity in the occurrence of parasites. 



Whiting (Merluccius bilinearis) were examined in the 

 months of March, June, July, August, September, Octo- 

 ber and November. Immature nematodes were found in 



