December 19, 1919] 



SCIENCE 



569 



ported in a previous paper'^ are confirmed. 

 Proven cultures from Vigna sinensis and 

 Glycine hispida were repeatedly stained and 

 examined, the organisms in every trial being 

 found to have a single polar flagellum. 



Attention was then turned to the organ- 

 isms, which had before given unsuccessful 

 stains owing to the more abundant slime pro- 

 duction. Pure cultures isolated from the 

 nodules of Trifolium pratense, Vicia villosa, 

 and Melilotus alba were tried, this time suc- 

 cessfully, though the staining of these organ- 

 isms is obviously more diiEcult and uncertain. 

 The bacteria in every case were found to 

 be peritrichous. It was further noted that 

 whereas the organisms of Vigna and Glycine 

 have a very stout flagellum, the flagella of the 

 organisms from Vicia, Trifolium, and Meli- 

 lotus are much finer. 



This confirms the work of De Rossi, Keller- 

 man, Zipfel, and Prucha (but one convincing 

 photomicrograph exists, that by De Eossi of 

 Tnfolum repens), and attention is called to 

 the fact that these workers . devoted their 

 efforts to the more slimy group, i. e., Vicia, 

 Trifolium, Pisum, Phaseolus, Medicago. 



It is now evident that on the basis of flagel- 

 lation, the nodule bacteria are to be divided 

 into two distinct groups; the Glycine-Vigna 

 group, and the Trifolium-Vicia-Melilotus 

 group. Further observations confirming this 

 grouping and dealing with cultural and phys- 

 iological characteristics as well as with the 

 systematic position of these and related or- 

 ganisms, will be the subject of a paper en- 

 titled, " The Nodule Bacteria of Leguminous 

 Plants " soon to be published by Lohnis and 

 Hansen. 



Roy Hansen 



Illinois Agricultural Experiment Station 



the supposed scales of the cottid fish 

 jordania 



The Cottidae are in general scaleless, but 

 the rare fish Jordania zonope Starks, from 

 Puget Sound, is said to have the body above 

 lateral line closely covered with ctenoid 

 scales. Dr. D. S. Jordan has very kindly 

 sent me fragments of one of the cotypes and 



illl. Agr. Exp. Sta. Bui. 202. 



the appearance is exactly as described. But 

 when the material is treated with hot caustic 

 potash, it is found that the apparent scales 

 are nothing more than rows of strong ctenoid 

 spines, placed as they would be in true scales. 

 In the dorsal region the rows are curved as 

 they would be were they margins of ctenoid 

 scales. In the presumably related fossil 

 Lepidocottus hrevis (Agassiz), from the Eu- 

 ropean Miocene, the ctenoid elements are as 

 in Jordania, but the complete scales are pres- 

 ent, with the circuli and basal radii as usual. 

 It must be supposed that Jordania came from 

 such an ancestor, and represents the survival 

 of certain elements of scale structure without 

 the scales, something like the gi'in of Lewis 

 Carroll's Cheshire cat. 



T. D. A. OOCKERELL 



REPORT OF THE COMMITTEE OF THE 



AMERICAN CHEMICAL SOCIETY ON 



THE PREPARATION OF A LIST 



RECOMMENDING CHEMICAL 



TEXTS FOR LIBRARIES 



On January 15, 1919, announcement was 

 made of the appointment of Messrs. W. A. 

 Hamor, A. M. Patterson, and L. C. ISTewall, as 

 a committee for the preparation of a text for 

 the use of librarians, in recommending books 

 for the chemical reading of the public, in ac- 

 cordance with the suggestion submitted to 

 President ^Nichols by Mr. Joseph L. Wheeler, 

 librarian of the Youngstown Public Library, 

 Youngstown, Ohio. Pollowing the presenta- 

 tion of its preliminary report^ at the Buffalo, 

 IST. Y., meeting of the society, the committee 

 membership was streng'thened by the addition 

 of Mr. Wilhelm Segerblom. 



The study of the needs of librarians which 

 was conducted by the committee at the incep- 

 tion of its work, made it clear that what was 

 most desired was an authoritative series of 

 reading courses, and not a mere book-list, on 

 chemical subjects. In fact, Mr. Wheeler form- 

 ally requested a mode of presentment consist- 

 ing of running texts so prepared that the 



1 See J. Am. Cliem. Soc, 41, 9.5-96 of Proceed- 

 ings. 



