ALTERNATIONS IN DISEASES. 569 



island of Uist (East) I saw lying upon the shore a cut of a large fir- 

 tree, about two and half feet in diameter, and nine or ten feet long, 

 which had lain so long out of the water that it was very dry, and most 

 of the shells that had formerly covered it were worn or rubbed off. 

 Only on the parts that lay next the ground there still hung multitudes 

 of little shells. This barnacle-shell is thin about the edges, and about 

 half as thick as broad. Every one of the shells has some cross-seams 

 or sections, which, as I remember, divide it into five parts. These 

 parts are fastened one to another with such a film as mussel-shells 

 have. These shells are hung at the tree by a neck, longer than the 

 shell, of a kind of filmy substance, round and hollow, and curved not 

 unlike the windpipe of a chicken, spreading out broader to where it is 

 fastened to the tree, from which it seems to draw and convey the mat- 

 ter which serves for the growth and vegetation of the shell and little 

 bird within it. In every shell that I opened I found a perfect sea- 

 fowl : the little bill, like that of a goose, the eyes marked, the head, 

 neck, breast, wings, tail, and feet formed ; the feathers everywhere 

 perfectly shaped, and blackish-colored ; and the feet like those of other 

 water-fowl, to my best remembrance." 



Many conjectures have been offered as to the origin of this strange 

 myth, and Max Miiller suggests the hypothesis that it came from the 

 early misapplication of terms. He remarks : " No man would have 

 suspected Linnaeus of having shared the vulgar error, nevertheless he 

 retained the name Anatifera, or duck-bearing, as given to the shell, 

 and that of JBernicula, as given to the goose." 



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ALTEKNATIONS IN THE INTENSITY OF DISEASES. 



FROM THE FRENCH OF ALPHONSE DE CANDOLLE. 

 TRANSLATED BY H. H. W. 



THE diminution of the efficacy of vaccination, as a preservative 

 from the small-pox, has been the subject, at first of incredulity, 

 and afterward of surprise, to the medical world, and even to the non- 

 professional public. The causes of this change have been sought in 

 the nature of the vaccine matter. But it has not been demonstrated 

 that taking the matter anew from the cow is to restore the primitive 

 efficacy of the remedy. 



Without wishing to call in question with the profession the chances 

 of discovering an explanation, drawn from the domain of medical and 

 physiological facts which they occupy, I desire to point out a conse- 

 quence of the fundamental law of heredity, as applied to the phe- 

 nomenon in question. In order to understand the subject in its true 



