2lS 



NATURE 



[May io, 19 17 



possible to correlate this feature with "selective ab- 

 sorption," for it is found that the organisms exhibit 

 jnarked absorptive power for just those rays which have 

 gfermicidal action. — E. C. Hort : Morphological studies 

 in the life-histories of bacteria. According to current 

 theory the life-history of the "lower" bacteria is one 

 of great simplicity, reproduction taking place — apart 

 from endosporulation, in certain cases, of a special 

 type— solely by transverse binary fission. This theory 

 is mainly based on the unquestioned fact that trans- 

 verse binary fission is the rule in standardised labora- 

 tory cultures. In thte present communication evidence 

 is produced to show that the life-cycle of the " lower " 

 bacteria, as illustrated by the members of the enteric 

 group, so far from being solely represented by per- 

 petual binary fission, is one of great complexity, and 

 includes an invisible, or almost invisible, stage. The 

 nature of the evidence presented excludes the presence 

 of contaminants, or of "involution" forms, as reason- 

 able explanations of the recorded observations, and 

 throws grave doubt on the adequacy of the mutation 

 theory to explain morphological aberrancy from type 

 — laboratory type — amongst the bacteria. 



Geological Society, April i8. — Dr. Alfred Harker. 

 president, in the chair. — Prof. H. H. Swinnerton and 

 A. E. Trueman : The development and morphology of 

 the ammonite septum. Two methods of studying the 

 septum (not merely the suture)' were used :— (i) Clean- 

 ing the face of the septum completely; (2) filing away 

 the surface of the whorl in successive layers, and thus 

 making a series of sections — called septal sections — of 

 the septum parallel to its periphery. An instrument 

 was designed for measuring accurately the variations 

 in level of the face of the septum in relation to a 

 definite datum-plane ; and also the thickness of the 

 layers filed off from the whorl. Dactylioceras com- 

 mune, Sphaeroceras brongniarti, and Tragophylloceras 

 loscomhi were chosen as types with normally shaped, 

 greatly depressed, and greatly elevated whorls respec- 

 tively. A contobred plan of the adult septum of Dac- 

 tylioceras shows that half the septum lies approxi- 

 mately in one plane and that the posterior folds or 

 lobes occupy a greater area than the anterior folds or 

 saddles. It also confirms the view that the septum is, 

 on the whole, convex forwards. In all three types the 

 axes of the folds remain approximately at right angles 

 to the periphery through all the changes in shape of 

 the whorl. Incompletely formed septa indicate that 

 secretion commences at the umbilical angle and at a 

 definite distance from the preceding septum Asym- 

 metry of the septum, and of the suture-line, in ammo- 

 nites is more common tiian is usually supposed. It 

 mav arise in one of two ways, namely, (i) by the 

 ■different development of the elements of opposite sides; 

 {2) in association with the lateral displacement of the 

 siohuncle. Asymmetry of the latter type has been con- 

 sidered as of svstematic importance. Nevertheless, 

 while it does arise more frequentlv in certain genera, 

 as. for instance, in Psiloceras and Hoplites, it occurs 

 not uncommonly in many other unkeeled ammonites. 



Mathematical Society, April ig.— Prof. H. M. Mac- 

 donald, president, in the chair, — Prof. W. Burnslde : 

 A liquid • gyrostat.— G. N. Watson : The integral 

 formula for generalised Legendre functions. — Prof. H. 

 Hilton : A substitution permutable with the transposed 

 substitution. 



May 3.— Sir J. Larrhor, vice-president, in the chair. 

 — G. H. Hardy : Sir George Stokes and the theorv of 

 ■uniform convergence. — Prof. E. W. Hobson : Hel- 

 linger's integral. — Dr. W. P. Milne : A symmetrical 

 condition for co-apolar triads on a cubic curve. 



NO. 2480, VOL. 99] 



Challenger Society, April 25.— Capt. Alfred Carpenter 

 in the chair.- Dr. S. F. Harmer : (i) A submarine 

 cable damaged by the bite of a shark; the injured 

 portion, brought up from a depth of 252 fathoms off 

 the west coast of South Africa, was pierced by the 

 tooth of a shark {Oxyrhina spallanzii). (2) Cetacea 

 stranded on the British coBsts during 1915 and 1916; 

 of special interest were examples of Cuvier's whale, 

 a very young sperm whale, a white-sided dolphin, and 

 a killer of very large dimensions.— E. Heron-Allen and 

 A. Earland : (i) A new type of Arenaceous Fora- 

 minifera; this showed a remarkably selective use of 

 entire sponge spicules of a single species. (2) An 

 unidentified enemy attacking Foraminifera; the enemy 

 organism sought to bore through the test of Bilo- 

 culina. 



Royal Anthropological Institute, May i. — Mr. A. L. 

 Lewis in the chair.— J. Reid Moir : Some human and 

 animal bones, flint implements, etc., discovered in 

 two ancient occupation-levels in a small valley near 

 Ipswich. The excavations, carried out over two years, 

 have shown that two well-marked occupation-levels 

 occur in the deposits covering the sides of the valley. 

 Since these floors were occupied by man the valley 

 has suffered denudation and erosion. The lowermost 

 floor has yielded animal bones, including elephant and 

 ancient types of horses, and three portions of the 

 human skeleton, viz., a skull fragment and part of 

 the shafts of a humerus and femur. These are not 

 referable to the same individual, but probably two 

 or three persons are represented. The associated flints 

 are of Upper Le Moustier type, and were associated 

 with fragments of primitive pottery. The upper floor 

 contains implements of the Aurignac culture, while 

 in the hill-wash overlying this floor two specimens of 

 Early Solutf^ implements have been found. The sur- 

 face soil above the hill-wash has yielded a tanged 

 and barbed Neolithic arrow-head. Thus an orderly 

 sequence of industries has been established such as 

 occurs in Continental caverns. The implements have 

 been examined bv Prof. v. Commont, who agrees with 

 the description of them given above. It would appear 

 that the hill-wash covering the upper floor was de- 

 posited during a period of low temperature occurring 

 at the close of Upper Palaeolithic times. 



Manchester. 

 Literary and Philosophical Society, April 3. — Prof. S. J. 

 Hickson, president, in the chair. — R. B. Fishenden : 

 Illustration processes used in scientific publications. 

 In the case of diagrams and other drawings in pure 

 line the most satisfactory results are obtained by the 

 use of a waterproof Indian or Chinese ink upon a 

 smooth hard-surfaced paper, or Bristol board. All the 

 lines must be equally black and firm ; if they are 

 broken, or have serrated edges, the defects generally 

 become more pronounced in the reproduction. Unless 

 it is impracticable for other reasons, the original draw- 

 ings should be made to be reproduced to half or two- 

 thirds their lineal dimensions. Photographs may con- 

 veniently be converted into line drawings by drawing 

 over the outlines with waterproof ink and then bleach- 

 ing out the original print. Photographs for reproduc- 

 tion by collotype or by the half-tone process are pre- 

 ferably black, glossy "bromide" prints, or " gelatino- 

 chloride " prints of a purple-brown tone. Sepia wash 

 drawings are more satisfactory for photographic repro- 

 duction than those made in pure black and grey. 



Paris. 

 Academy of Sciences, April 25. — M. A. d'Arsonval in 

 the chair.— H. Deslandres : The influence of intense and 

 prolonged gunfire on the fall of rain. Heavy rainfall 



