1883.] 



MICROSCOPICAL JOURNAL. 



213 



Cartcri and S. nUens ; the whole re- 

 minding one of the appearance of the 

 tetrahedral form of the sporangium in 

 certain plants. 



Perhaps I ought not to leave the 

 subject without making some state- 

 ment as to the way the young sponge 

 is produced from the statoblast, but 

 as 1 unfortunately have not seen the 

 process myself 1 may be allowed to 

 quote Mr. Carter, our present great 

 authority on the subject, as briefly as 

 I can : — 



'*In due season the cellular contents 

 are discharged through the foramen 

 into the water, and undergo a remark- 

 able development, appearing as a white 

 flocculent substance, having a Hat, 

 transparent, irregular margin, contain- 

 ing numerous vesicles, whilst in its 

 central portion are ova-bearing or re- 

 productive cells. At the same time 

 generally two kinds of spiculae appear, 

 which are formed in the interior of 

 special nucleated cells. They at lirst 

 present themselves as delicate lines, 

 but rapidly grow by external addi- 

 tions until they atta'.n full dimensions. 

 These additions are generally made 

 more quickly at one point than an- 

 other, rather than thorough out their 

 entire length, so that in their half- 

 developed condition they present one 

 or more bead-like inflations, which 

 disappear when the growth is com- 

 plete. 



" When the growth of the sponge- 

 mass has made some progress, the 

 formation of a distinct investing mem- 

 brane out of what was the flat trans- 

 parent border, becomes obvious. 

 This membrane is gradually detached 

 from the central ova-bearing cells, 

 either by the shrinking of the latter, 

 or by the protrusion of bundles of 

 spicules which force it outwards, leav- 

 ing here and there open spaces be- 

 tween the membrane and the central 

 cell-mass. 



" And so it proceeds until after the 

 development of other spiculjs and 

 canals formed for the passage of the 

 water, the sponge is perfected and 

 continues to grow by adding to its 



general structure, until it arrives at its 

 full size, which, of course, varies ac- 

 cording to the locality and species. 



* The process best suited for e.xam- 

 ining the structure of the statoblasts 

 in the dry state — which is the most 

 easy method, many ditificulties attend- 

 ing the examination fresh, when 

 attainable — is to place four or five on 

 a glass slip with a drop of strong 

 nitric acid. Boil this to dryness over 

 a very low spirit lamp. Do this three 

 times. Then place the slip on the 

 incline and pass water over it with a 

 caniel's-hair pencil until all the re- 

 mains of the acid is washed out. 

 Next with a sharp, thin knife like a 

 lancet, divide, in half or in quarters, 

 one or two more statoblasts, and ad- 

 just them round the remains of the 

 foregoing (or on a separate slip if you 

 prefer it). Add a dvop or two of 

 benzole or turpentine to keep them in 

 place, and when dry, which will be in 

 a few minutes, add a drop of Canada 

 balsam, cover with thin glass, previ- 

 ously just warming the cover, put the 

 slide in a warm place for some hours 

 to harden, and it will then be ready 

 for examination." 



Artificial Oyster Culture. 



The following paragraphs are taken 

 from Forest and Stream, and possess 

 much interest to microscopists : — 



" Mr. J. A. Ryder, a sped'al assis- 

 tant of the U. S. Fish Commission, 

 announces that he has successfully 

 reared the American oyster from the 

 egg at Stockton, Worcester county, 

 Md., on the grounds of the Eastern 

 Shore Oyster Company, during the 

 past summer, Messrs. H. H. Pierce 

 and Geo V. Shepard, of the above 

 iirm, kindly placing all facilnies at the 

 disposal of Mr. Ryder for carrying 

 out his work and afterward continuing 

 the experiments under his direction. 

 The apparatus was as simple as could 

 possibly be devised in order to insure 

 success, and was perfectly automatic 

 in its action. A pond was excavated 



