Dr. J. E. Gray on the Classification of Sponges. 445 



case, is the exception and not the rule ; if the example cited 

 is confirmed by future research, then polymorphism will be 

 one of the characters of the group. 



Amateur naturalists and microscopists often complain of the 

 brevity of the characters that I have given to the genera, 

 forgetting that it is only necessary to give a character which 

 separates it from the genera of the same family or section 

 of the family to which it is referred. To make this analytic, 

 the character often requires a considerable knowledge of the 

 subject and of the structure of the group, while almost any 

 body with a slight knowledge of the terms can easily make a 

 long description of a sponge, which will probably contain the 

 characters of the class, order, and family to which it belongs, 

 but very likely not contain the essential character of the special 

 sponge ; or if it does contain it, it can only be discovered by 

 repeated reading of the description, and comparison of it with 

 equally prolix descriptions ; so there can be no doubt of the 

 advantage of the analytic method and of the great improve- 

 ment that the Linnean system introduced. But to form them, 

 and, perhaps, properly use them, requires preliminary and 

 systematic study. 



Ellis, in his ' Zoophytes,' mentions the existence of glassy 

 spicules in sponges ; but, I believe, the first person who figured 

 them, and showed their structure in the different sponges, was 

 Jules Cesar Savigny, who figured several Egyptian species 

 which had spicules, in the large and expensive work, published 

 by order of Napoleon, to illustrate the history and antiquities 

 of Egypt. I do not think that Savigny ever published the 

 descriptions of his plates, the work being too large to be 

 finished, and Savigny having unfortunately become blind in 

 after life. It was one of the saddest of the many sad sights 

 I saw in Paris, when I visited the two great naturalists, viz. 

 Savigny and Lamarck, both stone-blind and suffering mostabject 

 poverty, I believe Savigny's only means of support was the 

 small allowance he had from the Academy of Sciences ; and 

 he had to wander to the meetings of that body, led by a boy, 

 that he might obtain the larger allowance given each time that 

 he made his appearance in person. The last decade of La- 

 marck's life was even still more sad and tragic ; but I believe 

 that I have already recorded the greater part of this in another 

 place. Indeed the end of the purely scientific man in France, 

 uninfluenced by any thing but the love of nature, is most 

 distressing. Fortunately I have never known men even 

 with far lower scientific pretensions in such distress in this 

 country. As soon as it was known that Ralfs was in diffi- 

 culties, his wants were most amply provided for by public 



