58 



THE MUSEUM. 



last year, is briefly touched upon; 

 while the alterations in colour, render- 

 ed so easy by the hiding of the older 

 by the more recently formed whorls 

 and the application of pearly matter 

 to the outside of the latter, is discus- 

 sed in some detail. 



Mr. Lydekker is unable to throw 

 any new light upon the object served 

 by the colouring of adult cowries, nor 

 does he suggest why the dark longitud- 

 inal bandings (which he calls trans- 

 verse) of immature shells, presumably 

 primitive and laid down by the edge of 

 the mantle, should often be replaced 

 by spots or uniform pigmentation de- 

 rived from the pallial surface. 



Nevertheless, the remarks show that 

 many interesting problems remain to 

 justify a further study of cowries, and 

 the paper affords a useful illustration 

 of the more striking types of colora- 

 tion. Perhaps the most striking of 

 the spotted series is not dwelt upon, to 

 wit, the form with, for instance, a 

 brown ground colour broken by white 

 spots; the larger of which in turn have 

 a very dark brown dot on their cen- 

 ter. 



The plate would have been better 

 entitled the markings of cowries seeing 

 that it is not coloured, and it is hoped 

 that it will not be taken as the best 

 that photography can do for the con- 

 chologist. One is constrained to say 

 conchologist, for the article ends with 

 an uncalled for outburst against the 

 biological method of studying molluscs. 

 At the beginning of the change for the 

 better about which Mr. Lydekker is 

 not correctly informed, attention wars 

 naturally turned to the "so-called ani- 

 mal," our ignorance of the habits of 

 which is so well brought out in the 

 "colours of cowries, " rather than to 

 the points in connection with the shells 

 which have been known for genera- 

 tions. 



Where Young Amateur Photo- 

 graphers Can Be of Assistance 

 to Science. 



BY DR. R. W. SHUFELDT. 



Of all the instruments that have 

 come into use in the hands of science 

 during the latter part of the present 

 decade, none of them have been found 

 so universally helpful as has been the 

 camera. The photographic camera, 

 with its modern multitudinous appli- 

 ances, has made its power felt in the 

 greatest variety of ways in all the de- 

 partments of science, as in physics, 

 chemistry, mechanics, astronomy, 

 zoology, and each and the rest. But 

 it is not my object to present an his- 

 torical essay here upon this instrument, 

 nor even to make the attempt to write 

 out all I know about the operation of 

 one, in its details; it is merly my aim to 

 bring a few practical hints before young 

 photographers, and show them some 

 of the new fields wherein, by patience 

 and study, they can put their instru- 

 ments to very excellent uses. As we 

 all know, the art of photography is now 

 easily acquired, and the producing of 

 photographic pictures a pleasurable 

 and sometimes a profitable employ- 

 ment. Yet how often it is, that we see 

 a young person purchase a first-class 

 camera with its entire outfit, and after 

 coming to be a good photographer, is 

 satisfied at the end of a year or so with 

 having filled a large album with pictures 

 of the country around about his or her 

 place of residence, or groups of friends, 

 and perhaps a few other subjects, when 

 the whole, save the album, is relegated 

 to a corner in the garret. This is by 

 no means a rare occurrence and the 

 end of such enterprises. 



I am a working naturalist, and a 

 number of years ago conceived the idea 

 that a good photographic outfit would 

 meet a variety of ends in the course of 

 my labors A hundred dollars gave me 

 one, and three times that amount of 

 money would not induce me to part 

 with it now. Including all my early 

 failures, more than fifty per cent, of 



