68 



THE AMERICAN MONTHLY 



[March, 



recommend its careful study by those 

 who desire to obtain an insight into 

 the methods and results of embryo- 

 logical study. 



Numbers 1-5 of volume IX of the 

 Bulletin comprise several reports of 

 the dredging under the supervision of 

 Prof. Agassiz in the Gulf of Mexico. 

 Among these are found a description 

 of new species of Asterias by Prof. E. 

 Perrier; a preliminary report on the 

 Mollusca, by W. H. Dall, and a very in- 

 teresting letter from Prof. Agassiz on 

 the distribution of living forms about 

 Key West and the Tortugas. 

 o 



Nuclei and their Structure. — 

 ' In Zoologischer Anzeiger Prof. Bal- 

 biani describes some curious struc- 

 tures in the nuclei of the salivary cells 

 of the larva of Chirononius plumosus 

 which correspond with similar struc- 

 tures observed by him in the nuclei 

 of certain other cells. In the large nu- 

 clei of the cells he describes two large 

 nucleoli with vacuoles, and besides 

 these a pale body, having the form of 

 a cylindrical cordon variously tv/isted 

 upon itself like an intestine. It has 

 a diameter about 0.015 "^"^- Usually 

 it is free in the cavity of the nucleus, 

 but in old larvoe it is often broken 

 into fragments, which may be either 

 free within tbe nucleus or fixed by 

 one extremity to the envelope of the 

 nucleus. When the cordon is continu- 

 ous, each of its extremities ends in one 

 of the nucleoli. Its substance is not 

 homogeneous, but exhibits transver- 

 sal striation as though made up of 

 alternate discs of clear and less trans- 

 parent material. It is said that these 

 structures can be readily seen in the 

 fresh cells, and, so far as we can learn, 

 without chemical treatment. 



Prof. Balbiani describes the action 

 of certain re-agents upon the cells. 



The structure described seems so 

 remarkable that we would like to 

 learn whether others can verify the 

 observations of Prof. Balbiani. 



The Microscope. — As we are not 

 slow to condemn what seems unwor- 



thy, we are more ready to commend 

 what is good. We are, therefore, 

 pleased to notice the greatly improved 

 character of Prof. Stowell's journal, 

 The Microscope, as revealed in the 

 February number. In it we find no- 

 thing to condemn, and we trust this 

 may always be the case in future. 

 May we not take some credit to our- 

 selves for this improvement? 



NOTES. 



— The office of the Scientific American 

 was destroyed by fire on the morning of 

 January 31st. Within two hours after 

 the fire, new and commodious offices were 

 leased, not far from the old place, and the 

 business of the publishers has suffered 

 but little interruption. Such promptness 

 and enterprise deserves commendation. 



— We are indebted to Messrs. J. W. 

 Queen & Co. for two very excellent micro- 

 photographs which, we believe, were made 

 expressly for them. One is of the late 

 President Garfield, and the other of Mr 

 and Mrs. Garfield. The original of the 

 former is by Sarony, the others were taken 

 by J. F. Ryder & W. J. Baker, of Colum- 

 bus. The price of these slides is 60 cents 

 each. 



— The eighth part of the Micrographic 

 Dictionary is now in the hands of sub- 

 scribers. The last subject treated is "Cy- 

 clops," and about one-third of the work is 

 now issued. The numbers have been is- 

 sued with great regularity, and they are 

 fully up to the standard of excellence de- 

 sirable in such a work. All the new plates 

 are valuable and accurate. Our subscrip- 

 tion list is already longer than we expected 

 it would be, and we are glad to notice this 

 as an indication of the increasing interest 

 in general microscopy in this country. 



— We are pleased to notice that Dr. J. 

 W. S. Arnold has offered his services to 

 microscopists who desire photographs of 

 microscopical preparations. We have fre- 

 quently been asked where such work could 

 be done, but have never been able to give 

 the desired information. Now, however, 

 those that cannot draw well, can have their 

 specimens photographed, and thus prepare 

 illustrated articles for publication, or for 

 other purposes. 



