148 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



through the shoal it will be found to be full of these 

 entomostracans. 



The surface groups do not appear to remain long 

 above at any time during the day, but dip to some 

 distance beneath ; and there, too, they are no doubt 

 followed by their enemies until the latter are gorged 

 or the shoal becomes too attenuated for further 

 pursuit. Those that most abound in the district 

 appear to be Calanus finmarchichus and Ternora 

 longicornis, and over the deep parts of Loch Fyne 

 Euchceta norvegica takes the place of Temora longi- 

 cornis. Peridinium tripos was in great abundance 

 last summer, at the surface and in trials of 20 

 fathoms. Some years ago the waters of Millport 

 Bay were crowded for a few days with Noctiluca 

 miliaris, which I have never seen since. Evadne 

 Nordmanni is occasionally abundant, besides a great 

 many others of less importance numerically, exclu- 

 sive of the multitudes of larval forms of Crustacea, 

 Echinodermata, Annelida, and Mollusca. 



We may assume that in studying the habits and 

 movements of fishes it is necessary that we should 

 know something of the habits and movements of 

 the animals on which they prey. In reference to 

 the herring, as they do not seem to take material 

 food during the formation of the roe and milt* 

 {which is generally believed among fishermen to be 

 about two-thirds of the year), I have examined 

 scores of them and never found food in their 

 stomachs when the milt or roe was more or less 

 advanced. At that time the stomach is contracted 

 to a small gut, which is often lined with a consider- 

 able amount of fat that may contribute to the 

 increase of the roe and milt during their fasting- 

 time. The gut-like stomach lies parallel to the roe 



* Since writing the above, Mr. Turbene, of the yacht Medusa, 

 tells me that he has seen large herrings taken off Camp- 

 beltown, full of roe or milt, with food in their stomachs. 

 This may have .arisen from their fat getting exhausted, and 

 food becoming necessary to sustain them over the spawning 

 period. 



