260 bulletin: museum of comparative zoology. 



only in May and June, while Cod occurred throughout the season; 

 and this, of course agrees with the well-known fact that the spawning 

 of Haddock in the Gulf is at its height in earl\- spring, while Cod have 

 long been known to spawn there throughout the year. 



It may, of course, be merely a coincidence that out of the hundreds 

 of eggs examined, so few have reached an advanced stage in develop- 

 ment. But in view of the general movement of water along the shore 

 of the Gulf from northeast to southwest, this fact is of considerable 

 interest, for it suggests the possibility that eggs spawned, for instance, 

 off Cape Ann, may hatch on Georges Bank. But much more extensive 

 data is needed to show whether such a migration actually takes place. 



Oceanographically, the restriction of newly spawned eggs to the 

 coastal zone is interesting, like the similar restriction of the ranges of 

 other neritic Metazoa (p. 251), as evidence of how slow the interchange 

 of water between the central and peripheral parts of the Gulf is; 

 and conversely, the large numbers of eggs encountered over the slope of 

 the Eastern Basin in May (Station 10270), where neither depth of 

 water, character of bottom, nor common report of fishermen suggests 

 the presence of Cod or Haddock in numbers, may well have been car- 

 ried there, from the neighboring slope of German Bank, which is a 

 well-known fishing ground, by the Cabot Current. 



Pollock Eggs. — The spawning of Pollock {Pollachius virens) has 

 long been known to reach its height, on the w^est side of the Gulf, in 

 late autumn and early winter. In 1915 Pollock eggs first appeared 

 in the tow on September 29 (Station 10321), when one was taken; 

 and occasional eggs of this species were taken on October 1st, 18th, 

 and 26th, (Stations 10323, 10330, 10336, 10337); about 150, all in 

 early stages in development on October 27th. 



The fact that these records are all from Massachusetts Bay, and 

 from Cape Cod, has no bearing on the distribution of Pollock eggs 

 in the Gulf, because no stations were located in its northern or eastern 

 part after October 15th, i. e., after Pollock spawning was well started. 



Silver Hake Eggs. — In 1915 the eggs of the Silver Hake (Mcrhicdvs 

 bilinearis) were found sparingly from June (Station 10284) until the 

 middle of October (Station 10331), at the localities shown on the 

 accompanying chart (Fig. 83). On four occasions they occurred in 

 large numbers, i. e., off Race Point, Cape Cod, July 7th (Station 

 10300); off Duck Island, Maine, July 19th (Station 10302); off Rye, 

 N. H., July 23rd., and near Monhegan Island, Me., August 4th 

 (Station 10303). Thus the Silver Hake spawns all along the shore of 

 the Gulf and off southeastern Nova Scotia, chiefly between the land 



