158 



THE AMERICAN MONTHLY 



[August, 



Diatoms from China. — M, Paul 

 Petit has published a pamphlet of 

 eight pages, with a fine plate (from 

 M^m. de la Soc. Nat. et Math, de 

 Cherbourg), describing some very 

 beautiful diatoms collected on oysters 

 from Ning-po and Nimrod Sound, 

 China. Figures are given of Cocco- 

 neis Ningpoensis, Pet. ; Achnanthes 

 subsessilis, Ktz. ; Triceratium rostra- 

 turn., Pet. ; T. Sinense ; Coscinodis- 

 cus lineatus var. oculatus, Pel. ; Raph- 

 oneis scuteilum, Ehr. ; Cyclotella Sin- 

 ensis, Ehr. The diatoms of China 

 are but little known, and good collec- 

 tions from there would be highly 

 prized by all students of these algae. 



CORRESPONDENCE. 



To THE Editor :— Will some one who 

 knows kindly inform me as to the best 

 way of catching, and holding for examin- 

 ation under the microscope, such minute 

 animals as the book-mite, etc. ? What 

 piece of apparatus is the best to use } 



W. 



To THE Editor : — On examining 

 some of the powder known as " Vegetable 

 Sozodont Tooth Powder," I found it to 

 be composed chiefly of diatomaceous 

 material, the forms being in both perfect 

 and fragmentary states. The other con- 

 stituent seemed to be some flavoring mat- 

 ter, which gives the powder its peculiar 

 taste. Various forms of Navicula and 

 Pinnularia occur in great abundance. 

 Also small and delicate forms. When 

 mounted in Balsam, the powder makes 

 an interesting object. 



I send you a sample herewith. 



C. W. G. 



Palisades, N. Y. 



NOTES. 



— Some time ago a correspondent hav- 

 ing seen a preparation by the Editor of 

 this Journal in one of the boxes of the 

 Postal Microscopical Club, showing the 

 nuclei of a species of Spirogyra stained 

 of a carmine color, asked how the stain- 

 ing was done. The process is very sim- 

 ple, and gives most excellent results. The 



plant was first killed by alcohol, and im- 

 mediately placed in a solution of carmine, 

 in which it remained several hours. The 

 carmine solution must be quite neutral or 

 it will not stain properly. The solution 

 actually employed was a neutral carmine 

 from Messrs. J. W. Queen & Co., which 

 had been permitted to stand uncorked 

 until it became slightly turbid from the 

 escape of ammonia, and the consequent de- 

 position of carmine. After the specimen 

 was well stained the excess of carmine 

 was washed out in water or glycerin. The 

 mounting was done in the ordinary way. 



— Dr. Georg Winter, the editor of 

 Hedwigia, announces that he hopes to 

 continue the issuing of Rabenhorst's Ex- 

 siccatae, with the concurrence of Mrs. Dr. 

 Rabenhorst, as heretofore. From the 

 present month until April next his resi- 

 dence will be Leipzig, Saxony, Emilien- 

 strasse, 18. 



— We desire to call the attention of our 

 readers to the slides of diatoms advertised 

 by M. Delogne. The preparer is well 

 known as a student of the diatoms, and 

 we are assured that whatever he sends 

 out in the way of mounted specimens, 

 will be entirely satisfactory. In his circu- 

 lar M. Delogne says : " It is useless, it 

 seems to me, to insist upon the value of 

 the study of diatoms, these pearls of the 

 water, as Bailey called them ; I will only 

 remark here that my collections have 

 been shown to Dr. Van Heurck, who 

 has figured a large number of forms 

 from these collections in the plates of his 

 Synopsis des Dtatomies de Belgique, now 

 in course of publication." Twenty-five 

 francs (about $5.00) for as many slides of 

 authentically named species is not a high 

 price ; and certainly those who have Dr. 

 Van Heurck's work would find the 

 mounted specimens very useful. 



— We are indebted to Surgeon J. J. 

 Woodward, U. S. A., for a series of nine 

 most admirable photographs of pseudo- 

 polypi from the colon, which were de- 

 scribed by him in the January number of 

 the American Journal of the Medical 

 Sciences. The photographs are remarka- 

 bly good, and tihey indicate great skill in 

 the preparation of the sections, which we 

 believe is characteristic of all the work 

 done under Dr. Woodward's supervision. 



— The editor of Botanical Gazette 

 states that the pellucid stems of Pilea 

 pumila (Richweed) are almost as valua- 



