JANUARY, 1883. 267 



for its victims, and prefer such an apparent " rest for its 

 banes," rather than torture, or something horribly 

 indefinite. It would be interesting to obtain a well- 

 authenticated series of cases of apparent "suicide by 

 animals." 



We have last week dredged our finest specimen of the 

 key-hole Limpet, Fissitrella Graeca, and thus satisfied 

 ourselves that they attain the ordinary size in our loch. 

 This proved to be a specimen of distinct interest, as both 

 in form and colour it far more approximated to the 

 variety gibba than to the ordinary form. As gibba is 

 figured of small dimensions, and we have specimens of 

 all intermediate shades of form between these two 

 varieties, we are satisfied that the two forms are merely 

 the customary variations of the one species, which, 

 although not so given to extremes of variation as our 

 common shore limpet, yet alter widely from the ordinary 

 accepted form. This must point to them as much more 

 common than their comparatively rare appearance in the 

 dredge would suggest, because we find that the more 

 numerous a species is the more widely will it vary within 

 certain limits. This is what would also be naturally 

 expected from the data on which the Theory of 

 Evolution of Species is based. 



" There is a black sheep in every flock " is an 

 old saying that we have heard variously interpreted. 

 Besides the obvious one that no large body of sheep 

 could be together without a black one, and no large 

 family without a scapegrace, we have been assured 

 that the black sheep meant "the dog" or "the 

 shepherd," and how we have a fresh notion imported 

 into the serious discussion. " What is there about a 

 black sheep," asks our friend, " that makes it not only 



