12 



THE SCIENTIFIC AND ECONOMIC ASPECTS 



commenced, and that these fish do not migrate into deeper 

 water in the late autumn but remain inshore until they die. 

 According to the statement of many fishermen, individuals of 

 this type sometimes compose 25 per cent, of a catch made 

 in the late autumn, and are invariably to be met with in a 

 true winter shoal. The present authors have been informed 

 by several fish curers and others at Newlyn and Mevagissey 

 that food is very seldom to be met with in the stomach of a 

 " shirmer," and there seems to be a fairly general opinion that 

 death is hastened by the fish's voluntary abstinence from 

 nutrition. It is important therefore to state that during the 

 present investigation the stomachs of numerous " shirmers " 

 have been examined, and that there appears to be no founda- 

 tion for this belief, a normal quantity of food having been 

 observed in the majority. In the series already mentioned two 

 of the six samples from Mevagissey Bay and three from 

 those taken in Mounts Bay were derived from " shirmers." 



A further attempt at observation on these winter shoals, 

 on this occasion directly on the Eddystone ground, was made 

 from a fishing vessel on the 31st of January, 1906, but proved 

 unsuccessful, only six pilchards being taken in a small mixed 

 catch, viz., three " shirmers," and three males with generative 

 organs fairly well developed. Examination of the stomach 

 contents showed food of a character entirely distinct from 

 that of the Portwrinkle fish referred to above : there was no 

 evidence whatever of any phytoplankton, the bulk of the 

 material being composed of fish larvae and ova, probably 

 those of herring, together with a slight addition of three species 

 of Copepods, Caradid larvae, Oikopleura dioica and Sagitta 

 bipunctata. The fish larvae and ova formed by far the greater 

 proportion of the sample in each instance, the stomach being 

 distended to some considerable extent by the amount of 

 materials contained therein. 



The comparison of these results with those obtained from 

 a series of plankton tow-nettings show certain remarkable 

 features. Fish ova Vv^ere recorded as rare, only occurring in 

 the oblique haul, and larvae were not observed in this netting 

 or at the surface. Phytoplankton, consisting largely of two 

 diatoms, Lauderia borcalls and Blddulphia inobiliejisis, pre- 



