116 JOURNAL OF THE [May, 



I have here the back setting of a i?-inch lens which was 

 made by me several years ago. The purchaser of the lens had 

 screwed it so tightly to his microscope that he could not, with 

 his hand, unscrew it. So he used a pair of heavy gas-fitter's 

 pliers, and succeeded in pulling the tube of the fine adjustment 

 out of the body of the instrument. This rude handling damaged 

 the microscope to the amount of forty-five dollars. 



Quite recently the owner of an instrument which cost three 

 hundred and fifty dollars told me that he had a wonderfully 

 clever son. " Why," he exclaimed, " he has, with a screw-driver, 

 taken the microscope all apart ! He is unable, however, to put 

 it together again." This outrage illustrates the incapacity of 

 some people, old, as well as young, to appreciate the products of 

 fine workmanship. 



I do not favor the nose-piece. If you must have one, choose 

 one that is of good design and thoroughly well made. Lenses, 

 especially those of high power, ought not to be tested with the 

 use of this accessory. 



A superior lens, worked by an illustrious microscopist, becomes 

 its maker's best advertisement. But when it falls into the hands 

 of a careless or incompetent person, and is not carefully used or 

 regularly and properly cleaned, to hold the maker responsible 

 for its consequent unsatisfactory performance is to do him great 

 wrong. 



SPONGES. 



BY PROF. HENRY J. RICE, SC. D. 

 {Given April 17M, 1885.) 



To the morphologist few forms of life present more interest- 

 ing objects of study than do the various members of the family 

 of sponges, since in their life-history are found typified certain 

 changes or conditions through which, modified to a greater or 

 less extent, almost all other animals have to pass in attaining 

 maturity. ' 



The general aspect of the sponge, and its habit of attachment 

 to some support, caused it for a long time to be considered a 

 vegetable. But when the distinction between animal and vege- 

 table life had become better understood, and the sponge itself 

 had been carefully studied, both as to its manner of growth and 



