420 THE CANADIAN NATURALIST. [Dec. 



locomotive when first detached from the parent, and in this state 

 the ' spat,' as it is called, must attach itself to some fixed objects 

 called ' cutch ' before it can be developed into the perfect native, 

 fit for educated human palates. Shells of dead oysters seem to be 

 the favorite ' cutch,' but mussel shells and shells of other mollusks, 

 and even pieces of earthenware and tiles, are not objected to. The 

 importance of dead oyster shells, to afford holding ground to the 

 new brood, was thus illustrated : 



" There are but few localities where the shells of the dead 

 oysters have accumulated in sufficient quantity to give the spat a 

 chance of adhering. It is, therefore, necessary to collect these 

 shells from elsewhere, and throw them down upon localities where 

 the spat is likely to fall. This process is carried out by oyster 

 culturists on a pretty large scale, and it seems almost providential 

 that beds of oyster shells should be found in the neighborhood of 

 the grounds which are cultivated. Thus, for instance, you will 

 see on the map, a place called ' Pan Sand,' at the mouth of the 

 Thames. Now, at this spot there is an accumulation of oyster 

 shells, and dredging boats from various localities dredge up these 

 shells, and carry them on to places nearer in shore and throw them 

 again to the bottom of the sea, knowing full well that if there be 

 spat floating about, and if they be in a proper condition to adhere, 

 that this cutch will assuredly catch it. How this Pan Sand oyster 

 bed came into existense I am quite unable to tell you ; but from 

 the appearance of the oysters themselves, I can assert that the 

 oysters were of great age, that they had lived there many years 

 undisturbed by dredgers, and that a considerable time has elapsed 

 since they thrived in this locality." 



The oyster culture is now a very important branch of business, 

 and I see that one sanguine theorist proposes to stock the whole 

 estuary of the Thames with live oysters, to feed them on the 

 sewage of London, and then, in turn, feed the whole population 

 of London on the oysters. 



The separation of physiology, or, as some prefer to call it, 

 biology, from technical zoology and botany, is an indication of a 

 somewhat important fact, namely, that those naturalists who have 

 devoted themselves to questions of comparative anatomy, of chemi- 

 cal physiology, and researches as to the nature of vital force and 

 the origin of species, regard questions of zoological and botanical 

 classification and of geographical distribution with impatience, 

 and are disposed more and more to separate themselves from the 



