2l6 



THE AMERICAN MONTHLY 



[November 



to read the proofs of the present 

 number of the Journal. It has been 

 fortunate both for him and for the 

 subscribers that his brother, Harlyn 

 Hitchcock, has been able and willing 

 to attend to many details connected 

 with the business and editorial con- 

 duct of the Journal since July, which 

 was the time of our expected return. 

 It is to his kind and opportune assist- 

 ance that the prompt issuing of the 

 Journal each month has been, in a 

 great measure, due. 



Having once more assumed imme- 

 diate supervision over the publication 

 of articles contributed by our numer- 

 ous correspondents — the number of 

 which, we are pleased to observe, has 

 been steadily increasing during our 

 absence — we hope to make the 

 Journal of still greater value and in- 

 terest than it has been in the past. 

 The opportunities seem greater now 

 than ever before, partly because of 

 the favorable circumstances for the 

 work afforded by the editor's connec- 

 tion with the National Museum, where 

 the comprehensive library at com- 

 mand greatly facilitates scientific work 

 of any kind, and partly for other rea- 

 sons. 



Correspondents will please observe 

 the change of address advertised 

 above. 



The Fresh Water Sponges. — The 

 interesting article by Mr. B. W. Priest, 

 which we publish this month, on the 

 statoblasts of the fresh-water sponges, 

 affords a good starting-point for the 

 microscopist who desires to pursue a 

 course of investigation. The author 

 of the paper referred to has given a 

 very full and clear summary of the 

 work already done in this field, al- 

 though there are a number of species 

 of fresh-water sponges not uncommon 

 in this country, but only recently de- 

 scribed, which probably escaped no- 

 tice when the article was prepared. 

 The reader may find references to, 

 and brief descriptions of, the Ameican 

 forms by looking over the indexes of 

 the last two volumes of this Journal. 



Sponges can be found in many 

 waters where their existence is not 

 suspected, if one will take a little 

 trouble to look for them at different 

 seasons. They occur in rapid streams, 

 and in ponds. In the former they 

 grow attached to stones and may be 

 easily detected, in shallow water, by 

 their green color. In ponds they are 

 often found on sticks and twigs 

 brought up from the bottom, or grow- 

 ing on the stems of water-plants, the 

 leaves of Vallisneria, etc. 



In reference to the preparation of 

 sponge-skeletons for microscopic spe- 

 cimens we have already several times 

 alluded to the use of Javelle water 

 for removing the soft parts, leaving the 

 spicules in their natural position, ^^'e 

 have not yet given it a trial, but are 

 hoping for an early opportunity to do 

 so. Unfortunately we have not been 

 able to obtain specimens of fresh 

 sponge to experiment with ; for, al- 

 though common enough at times, 

 sponges are not to be found in the 

 same places at all seasons. Mean- 

 while microscopists who live in the 

 country, with streams or ponds near 

 by, may find the inclination, as well 

 as the opportunity, to test the process, 

 when we would be pleased to publish 

 their conclusions. 



Plant-cells in Animals. — It has 

 been said that animal life is entirely 

 dependent upon plants, both for food 

 and oxygen. Among the higher or- 

 ders of life the physiological pro- 

 cesses take place independently, and 

 their mutual interdependence is only 

 observable after long study and in- 

 vestigation. It is now well understood 

 that the higher plants, under the in- 

 fluence of light, absorb and decom- 

 pose the carbonic acid gas which 

 results from the respiration of animals, 

 giving out pure oxygen in return, 

 which supports animal life. The plant 

 also prepares the food of the animal 

 out of the inorganic constituents of 

 the air, water or earth. One of the 

 most important products of the veg- 



