June 9 1910] 



NATURE 



447 



J „.-oe, metanitrobenzoic acid proved most efifectual, the 

 (process being capable of accurate quantitative results. 

 Soon after those experimental papers appeared the author 

 ■commenced similar researches, hoping to find an organic 

 reagent which would be a precipitant for some of the j'ttria 

 earths — if not with quantitative accuracy, at all events with 

 sufficient separation to allow a fractionation method to be 

 based on the reaction. His results, not being sufficiently 

 definite, were never published ; but as the organic acids 

 were in his laboratory when the scandium research was 

 <ornmenced, he preferred to use these acids, of which the 

 purity and the history were known, rather than start afresh 

 with acids of unknown history. — ^J. Eustice : Flow of 

 A\-ater in curved pipes. Experiments were made on a 

 flexible tube with the object of ascertaining the increased 

 resistance to the flow of water which is due to the curvi- 

 linear motion of the water in coils of uniform radius. The 

 tube, which was about 0-37 cm. internal diameter in its 

 normal condition, was sufficiently small to admit readily 

 of experiments both below and above the critical vek)cit>-. 

 In order to separate the effect of curvature and change of 

 cross-section, special apparatus was emplovecf to change the 

 section of the straight tube from circular to oval form. 

 ■Comparisons were made between the flow in the straight 

 tube and the flow in the tube when it was coiled, the 

 straight tube and the coiled tube being of the same form 

 and area of section. The results obtained show that : — 

 (a) The flow in a straight flexible tube of circular section 

 ■follows the laws of flow in metal tubes as investigated 

 by Prof. Osborne Reynolds, and that the vek)city at which 

 turbulence commences is given by Revnolds's formula, 

 (fe) The critical velocity,-, which is so we'll marked in the 

 flow in a straight tube, appears to be entirely absent when 

 tube is coiled, that is to say, the index la'w for straight 

 5 does not hold for coiled tubes, (c) The increased 

 =tance due to the curvature of the tube length is repre- 

 d by the formula (AV/\'1» = CR-', where AV is the 

 of velocit)' due to coiling the tube, V is the velocity 

 I in a straight tube of the same form and area of section, 

 ; R IS the radius of the coil, and C is a constant for anv 



! -given velocity V, but both n and C varv with V. Prof \ 



Dentiy and G. E. Nicholls : The occurrence of a " mesV 

 coehc recess " in the human brain and its relation to the 

 «ub-commissural organ of lower vertebrates, with special 

 reference to the distribution of Reissner's fibre in the 

 vertebrate series and its possible function. The authors 

 find m the adult human brain a small cavity, lined by a 

 characteristic columnar epithelium, imbedded in the roof 

 ■of the Iter at the back of the posterior commissure, and 

 in close relation to this another irregular cavin% which 

 apparently represents the remains of a communication with 

 the lumen of the iter. In the five months' foetus this com- 

 munication is sHlI widely open, and the cavity in question 

 IS evidently part of a structure Iving beneath the posterior 

 ^mmissure, and corresponding to the so-called " epen- 

 dymal groove " of lower vertebrates. For this structure 

 tne authors now propose the more distinctive term " sub- 

 commissural organ." It consists, in the human fcetus, of 

 .wo bands of high columnar epithelium \K'ith deeplv situated 

 nuclei, invaginated posteriorly into the roof of the iter to 

 lorm a mesoccelic recess." as in certain lower vertebrates, 

 in the adult man it is in a vestigial condition, being re- 

 presented by the mesoccelic recess alone. In the chim- 

 panzee the sub-commissural organ is better developed than 

 in man and the mesoccelic recess still opens into the lumen 

 ot the tter m the adult, the recess itself having a diameter 

 nearly ten times as great as in the human subject. The 

 condition of the sub-commissural organ in the cat and the 

 mouse IS also described and figured for purposes of com- 

 parison. In these two tv-pes it is very well developed, and 

 I.n'/ '\^'^ a Reissner's fibre. The latter, in tfie cat 

 (and probably also in the mouse), breaks up into slender 

 Branches, which are connected with the modified epithelium 

 Of the sub-commissural organ, exactlv as in lower verte- 



reTatlnn ^f ■ u •"'P''--';' L?^^- ^Considering this well-defined 

 relation of Re.ssner's fibre to the sub-commissural organ, 

 r J!^^^ ^f^^^ improbable that in man. where the lub^ 



shut nff T "'.f " '^ ""^^i"^ *« = '"^'■^ ^'^t'g« altogether 

 shut off from the remainder of the caviu- of the brain, a 

 tinn?"^"" ^ ^'''■^e^'sts. It is maintained that these observa- 

 tions support the view already put forward that Reissner's 



NO. 2 119, VOL. 83] 



fibre has a mechanical and not a nervous function, and 

 that, in connection with the sub-commissural organ, it 

 j forms an apparatus for automatically regulating (in lower 

 j t>"Pes) the flexure of the vertebral column ; this function is 

 I supposed to have become obsolete with the assumption of 

 ! the erect position and the loss of the tail. 



i Zoological Society, May 24. — Dr. Heniy Woodward, 

 1 F.R.S., vice-president, in the chair. — D. G. Lillie : 

 i Observations on the anatomy and general biology of some 

 ] members of the larger Cetacea. This paper was the out- 

 } come of seven weeks spent at the Irish whaling station 

 i during the summer of 1909. The object of the visit was 

 j to make a preliminarj' survey of the opportunities which 

 j are now offered for a study of the larger Cetacea by the 

 j recent establishment of whaling stations off the shores of 

 I the British Isles. A list was given of the species captured 

 I at the Irish station during the two years of its existence, 

 j with notes on the species Balaenoptera musculus, Linn., 

 ' B. sibbaldii, Gray, and Physcter macrocephalus, Linn., 

 which were seen by the author. The paper also contained 

 observations on the occurrence of hairs in whales, the 

 ; auditory organ of the Balzenoptera, the asymmetry of the 

 odontocete skull, and a few remarks upon the habits of 

 whales. In conclusion, attention was directed to the pre- 

 ■ sent difficulty in obtaining information as to their method 

 of copulation, period of gestation, rate of breeding, &c., 

 and a means of overcoming this difficulty was suggested. — 

 C. F. Rousselet : Collection of rotifera made by the 

 third Tanganyika expedition, 1904-5. Amongst the speci- 

 mens brought back by Dr. W. A. Cunnington were a 

 number of tubes containing fine surface plankton nettings 

 from Tanganyika and other lakes of that region. These 

 the author searched for rotifera, and the result was con- 

 tained in the present paper. From Lake Tanganyika only 

 eleven species were obtained, all already known in other 

 parts of the world, whilst the River Lofu, which enters 

 the lake at its south-western corner, yielded twenty-three 

 species, one of which is a very remarkable new kind. In 

 Lake Nyassa only six species were found, and a single 

 gathering of V^ictoria Nj-anza yielded nine species. This 

 collection is interesting and important from the fact that 

 no previous record of rotifera from Lake Tanganyika had 

 been made, and very few species were known from the 

 Central .African region. — ^J. Ritchie : (i) The hydroids of 

 the Mergui Archipelago, collected by Mr. J. J. Simpson 

 and Dr. R. N. Rudmose Brown ; (2) the hydroids of 

 Christmas Island, collected by Dr. C. W. Andrews, 

 F.R.S. The chief interest of these two papers was 

 faunistic. In the former thirt}' species were recorded, in 

 the latter thirteen. It was apparent that the hydroid fauna 

 of the eastern Indian Ocean, of which hitherto little had 

 been known, lacked distinctness, and that its closest 

 affinities were with the faunas of the neighbouring Malay 

 -Archipelago and Australian areas. 



Institution of Mining and Metallurgy, May 26. — Mr. 

 Edgar Taylor, president, in the chair. — ^T. J. Hoover : .A 

 standard series of screens for laborator\' testing. This 

 paper represents an attempt on the part of the author to 

 reconcile the conflicting elements in the existing series of 

 screens, such as the " common " series, Rittinger's, 

 Richards's, De Kalbs's, and the I.M.M. Standard Screens, 

 and to present in their place a " cube root " series, for 

 which he claims merits hitherto wanting ; also to present 

 a practical mechanical method of making screen analyses. 

 With these ends in view, after a brief reference to the 

 functions required in laboratory- screening, the author pro- 

 ceeds to analyse in detail the various series of screens 

 mentioned, and of his proposed substitute, and to compare 

 them w-ith silk bolting cloth. Subsequently he directs 

 attention to a machine calculated to simplify' the operation 

 usually accomplished by means of hand-sizing tests. .An 

 ample bibliography concludes the paper. — H. Stadler : 

 Grading analyses and their application. This paper gives 

 in detail the results of a number of tests made by" the 

 Mines Trials Committee in South .Africa, from which the 

 author proceeds to show how the various portions of certain 

 standard sizes of particles may be valued in units of energy 

 which will allow of an exact expression of the efficiency of 

 the crushing operation for purposes of useful comparison. 

 He claims that the most rational and logical system of 



