1883.] 



MICROSCOPICAL JOURNAL. 



215 



known from the preparations sold by 

 the dealers in foreign slides. These 

 are not very widely distributed, and 

 as the mounted shells are not only in- 

 structive as illustrating the develop- 

 ment of the oyster, but also very 

 beautiful objects, the editor of this 

 Journal has obtained a small quan- 

 tity of the spat, and preserved it in 

 fluid for distribution among the sub- 

 scribers to the Journal. 



It was rather late in September be- 

 fore the idea to do this occurred to 

 him, and for this reason the quantity 

 obtained was less than would be de- 

 sirable for this purpose. However, a 

 plan of distribution has been devised 

 which will doubtless enable all sub- 

 scribers who desire specimens to ob- 

 tain enough for several slides. Mrs. 

 Hitchcock has kindly offered her as- 

 sistance in distributing the material, 

 so that the editor will be relieved of 

 the necessity of giving personal at- 

 tention to it. Subscribers who desire 

 to receive specimens are therefore re- 

 quested to address Mrs. R. Hitchcock, 

 post-office box 630, Washington, D. C, 

 enclosing a three cent stamp, to cover 

 the expenses of return postage. They 

 will receive in return, as soon as the 

 material can be properly cleaned and 

 divided for distribution, a sufiticient 

 quantity for several slides of the best 

 quality. 



The young oyster shells resemble 

 minute, transparent, and perfectly 

 formed clam shells. They are beauti- 

 ful objects for the microscope how- 

 ever they may be mounted, but there 

 are three ways to be recommended, 

 as giving a variety of effects. To 

 have the shells perfectly clean it is 

 well to wash them with clear water 

 before mounting them. Then pn)- 

 cet-d as follows : — 



To mount them in balsam select a 

 clean slide, place a drop of the water 

 containing the shells on the centre, let 

 the water evaporate, and apply thin 

 balsam in the usual way, avoiding 

 pressure on the cover glass. Speci- 

 mens mounted in balsam make fine 

 objects for the polariscope. Perhaps 



the dry-mounted shells are most fre- 

 quently met with. To mount them 

 dry, make a shallow cell with an 

 opaque, black ground, and place upon 

 the latter some of the shells in a drop 

 of water. Add to the drop the least 

 trace of gum from a very dilute solu- 

 tion of gum Arabic in water. When 

 this is mixed with the drop, draw olT 

 the excess of fluid with a camel-hair 

 brush, and allow the shells to dry 

 thoroughly. The small quantity of 

 gum left will cause them to adhere 

 well to the bottom of the cell. The 

 cover may then be applied. 



Frequently the young shells are 

 mounted in fluid so that they may 

 freely move about when the slide is 

 inclined. They then make very beau- 

 tiful objects for the polariscope, as 

 they roll about in the liquid when the 

 slide is examined on an inclined 

 stage. The cell should be deep 

 enough to let them move freely. A 

 shellac cell will do very well, and 

 water is a good medium to mount 

 them in. 



EDITORIAL. 



All communications relative to business matters, 

 should be addressed to the publishers, S. E. Cassino 

 X: Co , 41 Arch Street, Boston, Mass. 



Contributions, exchanges, and letters pertaining 

 to the editorial management, should be addressed to 

 the Editor, P. O. Box 630, W'asbington, D. C. 



SUBSCRIPTION-PKICE, ji.oo per year, in advance. 

 Subscriptions begin with the January number, unless 

 otherwise ordered. Address, S. E. Cassino & Co., 

 Boston. 



Exchanges. — Publishers and ed- 

 itors who favor us with their publica- 

 tions in exchange are requested to 

 note the change in the editor's address. 

 All exchanges and books for review 

 should be addressed to the editor. 

 Post Office Box 630, Washington, 

 D, C, 



Home Again. — After an absence 

 in England, unexpectedly prolonged, 

 the Edi.or has returned just in time 



