20 THE POPULAR SCIENCE MONTHLY. 



at the bar : " Come, Swill, let's take a drink ! " " Well, I don't know. 

 Ain't dry myself. Hows'ever, guess I will take a drink, for fear I 

 might get dry ! " With better philosophy on their side, these edu- 

 cated oysters, twice in every twenty-four hours took their precaution- 

 ary drink. The French method of oyster-training is much more 

 laborious. The adult bivalves are carefully spread out in the water 

 and periodical lessons are given to each one individually. Each oyster 

 on this occasion receives a tap, not with a ferule, but with a small iron 

 instrument. This causes the bivalve to close tightly. Finally the last 

 day comes with its last premonitory tap. Its education thus finished, 

 it takes passage with its fellow-graduates for Paris. As a result of 

 its education, it knows how to keep its mouth shut when it enters 

 society ! 



Said one of the English commissioners at the great World's Fair, 

 in respect of the American inventions on exhibition, " They show so 

 much knowingness ! " So we think of this oyster-training ; the Amer- 

 ican practice shows a common-sense tact, not found in the French 

 method. And, though in a vastly more ancient sense, the secret of 

 keeping oysters alive in the winter is an American art. Connected 

 with the inland deposits of oyster-shells, made by the former Indian 

 tribes in New Jersey, the writer has discovered what he believes to 

 be oyster-preserves, the evidence of pits in which the Indians stored 

 the living bivalves for winter consumption, when the bays and rivers 

 of New Jersey were frozen over. While unearthing this Indian 

 cache, the thought occurred, " How knowing these ancient people 

 must have been ! " 



The next article will give, in detail, the friends and companions 

 of the oyster ; its enemies, with their modes of attack, and the geo- 

 graphical area of this bivalve. 



-*- 



HERBERT SPENCER AND THE DOCTRINE OF 



EVOLUTION. 1 



THE change that has taken place in the world of thought within 

 our own time, regarding the doctrine of Evolution, is something 

 quite unprecedented in the history of progressive ideas. Twenty years 

 ago that doctrine was almost universally scouted as a groundless and 

 absurd speculation ; now, it is admitted as an established principle by 

 many of the ablest men of science, and is almost universally conceded 

 to have a basis of truth, whatever form it may ultimately take. It is, 

 moreover, beginning to exert a powerful influence in the investigation 



1 A Lecture delivered before the New York Liberal Club, June 5th, 1874, by E. L. 

 Youmans. 



