February 13, 190S] 



NA TURE 



545 



are truly given off by the fibre, and are not merely 

 coagula, I have not yet been able to determine. 



In transverse sections a definite sheath to the fibre can 

 be seen, although the fibre itself is not readily made out 

 in these sections until a certain familiarity with its course 

 has first been obtained from an examination of sagittal 

 sections. In the one fibre measured, the diameter was a 

 little more than 6 p.. 



I did not find in any of my preparations that the fibre 

 lurkd up into the " tangle " or " snarl " as described by 

 Simders in My.xine, bv Dendy in Geotria, and mentioned 

 by Sargent as commonly occurring, but this may probably 

 be attributed to the precaution that was taken in every 

 case thoroughly to fix and harden the central nervous 

 system before severing the spinal cord. (The brain and 

 spinal cord of several of the smaller specimens were cut 

 entire in sagittal sections.) In all cases the central nervous 

 system was dissected out entire from the freshly killed 

 animal, and, where practicable, under the actual preserving 

 fluid. Zenker's fluid, which did not admit of this, gave 

 less satisfactory results than Flemming's stronger fluid. 

 The stain employed was a modification of Weigert's 

 suggested by C. Judson Herrick. 



I have compared the fibre seen in sections so prepared 

 with that shown in sections of FeUomyzon fliiviatilis in 

 the laboratory collection at King's College, and also with 

 that shown in Prof. Dendy's Geotria sections, which were 

 prepared by altogether different methods, and the com- 

 parison leaves no doubt in my mind that we have here to 

 do with a perfectly normal structure, and one cannot 

 but express wonder that an object so clearly defined should 

 have for so long escaped notice in the frog. 



George E. Niciiolls. 



icing's College, London, February 6. 



Rhynchobdella aculeata in Ceylon. 



It seems worth while to make a special note of the 

 occurrence of the above-named food-fish in the inland 

 waters of Ceylon, lis near ally, Mastacembcliis armalus, 

 has long been known to .occur here. The general 

 Ceylonese term for fishes belonging to the family Rhyncho- 

 bdellidae, commonly known as " spined " or " thorny- 

 backed eels," though not nearly related to the true eels, 

 is " telliya, " but the natives distinguish between the " Gang- 

 telliya " (river-telliya), which is Mastaccmbclus armatiis, 

 and the " Batakola-telliya " {alluding to the lanceolate 

 form of the body), which is Rhynchobdella aculeata. The 

 laller is reputed to grow to a length of 15 inches, and I 

 recentiv examined one of 12 inches. In the former, 

 commoner species, the vertical fins are confluent and the 

 dorsal spines are numerous (about thirty-eight) ; in the 

 second species, which has not previously been recorded 

 from Ceylon, the dorsal and anal fins are separated from 

 the caudal by a notch above and below ; the dorsal spines 

 are less numerous (sixteen), and the long, fleshy snout, 

 which gives these fishes such a remarkable, antiquated 

 appearance, is transversely ribbed below. The identification 

 is therefore not open to doubt. 



The Rhynchobdellida:', as a family, are " excellent as 

 food," to quote the words of the late Dr. Francis Day, 

 and the hitherto unsuspected presence of an important 

 member of the family in Ceylon affords an illustration of 

 the incompleteness of knowledge concerning the biological 

 conditions of the local inland fisheries. The batakola- 

 telliya is stated to be absent from Malabar, a peculiarity 

 of distribution which ranges it roughly in the same 

 catpgorv with Chautia orientalis, Polvacanthus signatus, 

 and perhaps a few other fresh-water fishes. 



Artir-r Willev. 



Colombo Museum. January 20. 



Poseidonius on the Originator of the Theory of Atoms. 



In .'<trabo's "Geography," book xvi., chapter xi., § 24, 

 in the description of SIdon, we find the following 

 remark : — 



" If we are to believe Poseidonius, the ancient opinion 

 about atoms originated with Mochus, a native of Sidon, 

 who lived before the Trojan times." 



This tracing of the theory of atoms to an authority 



NO. TQg8, VOL. 77] 



much more ancient than Democritus does not seem to be 

 mentioned in any of the works on physics, but as it is 

 from the usually accurate Strabo, and rests on the high 

 authority of Poseidonius, it seems worthy of notice. 



T. J. J. See. 

 Naval Observatory, Marc Island, California, 

 January 27. 



AGRICULTURAL AND HORTICULTURAL •, 

 RESEARCH.^ 

 VTO better evidence can be adduced of the growing 

 '■^ interest in agricultural education and research 

 in this country than the support which has been given 

 to thein by the county councils of Surrev and Kent 

 during the last few years. They have materially 

 promoted the science of agriculture and horticulture 

 by furnislning the necessary means for the annual 

 publication of such valuable reports as the one which 



FiC. I. — C.ooseberrj-shoot attacked by the .\meriL.ln Gooseberry-mildew 

 numerous dark scurfy patches of the spawn of the mildew can be seen 

 on the stem. 



has recentiv been issued from the South-eastern -Agri- 

 cultural College at Wye, Kent. 



The report gives the results of an immense amount 

 of painstaking investigation, and the exhaustive way 

 in which the subjects are treated will be appre- 

 ciated when it is realised that a bulky volume of 438 

 pages has been produced by the combined labours of 

 the various members of the staff. The work is well 

 written, and the different subjects are presented with 

 pleasing freshness. Altogether we feel that it will 

 prove a veritable mine of immensely valuable infor- 

 mation, enhanced in no small degree by some of the 

 most beautiful half-tone illustrations which we have 

 yet seen in a work of this kind. 



5 University of London. "The Journal of the South-eastern Agricultural 

 Colleee, Wye, Kent." No. rfi. Pp. ix-(-428. (London and Ashford, Kent : 

 Headley Brothers, 1907.) Prici 6tf. ; for Residents in Kent and Surrej*, 3J. 



