MILNER FISHERIES OF THE GREAT LAKES. G7 



spawn of the lake-herriug was obtained and treated similarly to the 

 white-fish ova. It is stated that "their time of incubation is about the 

 same [as the white-fish. J The newly-hatched fish are very small, not 

 exceeding three-eighths of an inch in size. The umbilical sac lasts but 

 a few days, and the fish begin to swim and feed as soon as they come 

 out of the shell. They are as active at one day old as the trout at two 

 months. The young fish, being so small and delicate, are, of course, 

 hard to keep. * * * They have increased in size faster than the 

 white-fish, and the indications are that they are a more hardy fish and 

 more easily raised." 



The ovaries of a specimen examined weighed two ounces, and con- 

 tained sixteen thousand and forty eggs. 



At Waukegau, III., from a seine-haul on the 23d of June, a num- 

 ber of young herring were swept in with the larger fish, measuring from 

 three and one-third inches to four and a half inches. At the rapids of 

 the Sault Ste. Marie Eiver a number were taken, from among the rocks 

 near the shore, on the 2d and 3d of July, that measured from two and 

 five-eighths inches to six inches in length. It is probable that the 

 smaller grade were the fishes hatched the previous year. 



On the 3d of December last herring were taken with a minnow-seine^ 

 at Point Edward, measuring from five inches to the size of mature fishes^ 

 the smaller ones being in all probability the same generation as those 

 found at the Sault Ste. Marie earlier in the season. 



Besides its enemies among the spawn-eaters, the herring has much 

 the same class of enemies as those already enumerated for the white- 

 fishes. 



Of the parasites the most marked species is a Botlirioceplialm found 

 in the muscles of the dorsal region. They measure two or three inches 

 in length and are found in masses between the intermuscular fascia? of 

 the back. The specimen in which the parasites were found was taken in 

 Detroit River in the month of April, and though not observed after the 

 month of June, it is certainly common earlier in the season, as the fish- 

 ermen are familiar with the fact. A parasitic worm has also been seen 

 in the intestine. 



The external parasite of the white-fish, a Lenuea, was not seen at- 

 tached to a single specimen of the lake-herring where hundreds were con- 

 tinually passing in the confined ponds of Detroit River, though they 

 were seen to be very common on the white-fish. Xor were any specimens 

 of the EchiHorliynchus found in the intestines, though a white-fish is 

 seldom examined without finding them numerous. 



24.— THE LAKE-STURGEON, Aci])€ns€r ruUcunclus. 



(24 a.)Sinioiujmy.—Acii)€nst'rruhicioidus,J.-E.fi\JY.\m, Trans. Amer. Phil. 

 Soc, (uew'^ series,) i, p. 388, pi. 12 ; Richardson, Faun. Boreal. Amer., 

 iii, p. 281; FiTZiNGER and Heckel, Ann. T\len. Mus., i, p. 310 ; DeKay, 



