April 6, 1905] 



NATURE 



549 



When a second pot is opened two and a half or three 

 days after the eggs have been placed therein, and portions 

 of its contents are examined in the same way, a larger 

 proportion of empty egg-cases will be seen. There may 

 be very few or even no developing rotifers still within 

 the eggs, and in other egg-cases, instead of the motion- 

 less vesicular contents previously seen, great ciliates may 

 be found slowly revolving, or, under the influence of the 

 light, rupturing the egg-case, struggling out, and swim- 

 ming away with rapid movements, partly of rotation. 

 Some of the Infusoria before they emerge undergo 

 segmentation into two, four, or rarely, even into eight 

 smaller ciliates. 



The large undivided Infusoria have their bodies densely 

 packed with large corpuscles (modified representatives of 

 the vesicles of an earlier stage), and a large elongated 

 nucleus which can be readily seen in some of them. They 

 possess the characteristic e^ir-shaped mouth indicated by 

 the name Otostoma, and cilia are distributed all over 

 the body in longitudinal lines, so as to give the appear- 

 ance of a delicate longitudinal striation. 



.As a control experiment it will be well at the time that 

 the pots are charged to place two or three batches of the 

 eggs with some of the same water into a watch glass, 

 which is left exposed to light ; and at the expiration of 

 three or four days, as well as at later periods, to search 

 among its contents for any of the same large ciliates, and 

 also for any eggs in the intermediate vesicular stage above 

 referred to. The author has invariably found that such a 

 search yielded only negative results. 



In taking batches of eggs, in the manner indicated, 

 to be placed in the pots, individual eggs will necessarily 

 be of different ages. It is only eggs that have not begun 

 to develop which, under the cutting off not only of 

 ordinary light, but probably of some invisible light rays, 

 become speedily transformed into great ciliated Infusoria. 

 Cutting off ordinary light rays alone from the eggs, by 

 placing them in a small covered glass dish shut up in a 

 cupboard or box and maintained at the same temperature 

 as before, seemed at first not to lead to similar results, but 

 it was subsequently ascertained that the transformation will 

 occur under such conditions, though only after the lapse 

 of about nine days. It looks, therefore, as if the stoppage 

 of some invisible rays, capable of passing through wood 

 but not through stone, notably hastens the process. 



During the time that these observations were being 

 made, and previously, no Otostomata had ever been seen 

 in association with Hydatinae, except those that had been 

 taken from the experimental vessels. On two occasions 

 since, though from wholly different localities, Otostomata 

 had been found in association with Hydatins. The adult 

 forms have been found to be much larger, having from 

 two to three times the length of the great embryos which 

 issue from the egg-cases, and also to be more highly 

 organised. 



Many of these adult specimens the author has been able 

 to keep for two months, and he has seen them pass into 

 an encysted condition, when they constitute masses the 

 bulk of which is several times greater than that of Hyda- 

 tina eggs. They are, lilcewise, enclosed in thick cyst 

 walls, wholly unlike the thin egg-cases of the Hydatina. 



A Hydatina e^s^ could not possibly be confounded with 

 an adult encysted Otostoma, and the embryo Otostoma 

 which emerges from the egg-case embodies the whole of 

 the transformed substance of the egg. ^o minute 

 Otostoma is ever to be seen within an egg, devouring its 

 contents. No ciliate is seen until the total contents of the 

 egg having been transformed, the whole mass begins to 

 revolve within the egg-case as a great embryo Otostoma. 



(2) The Origin of Twelve to Twenty Vorticellae or 

 Oxytrichae from the Substance of a Single Hydatina Egg. 

 — These are most remarkable variations, which at different 

 times have been occasionally met with in Hydatina eggs 

 taken from the experimental vessels. 



If the egg-substance is found to have segmented into 

 twelve to twenty more or less equal spherical masses, there 

 is at first no means of knowing whether such masses are 

 to be developed into embryo Vorticellae or into embryo 

 Oxytrichs. But if either of the masses is seen to be re- 

 volving within its own delicate cyst, we may be sure that 

 this particular egg will not yield Vorticellae, as these 



NO. 1849, VOL. 71] 



embryos do not revolve before rupturing their cysts, and 

 the Hydatina egg produces either the one or the other 

 form — never a mi.xture of the two. 



It cannot be supposed that twelve to twenty of either 

 of these ciliates in an embryo condition could penetrate 

 the egg-case, could devour its contents without being seen, 

 and would then, as embryos, encyst themselves (all in two 

 days, or less) — only, almost immediately after, again to 

 pass out of their encysted condition, and to appear as the 

 active young Vorticello? or O.xytrichjE the development 

 of which the author has traced. 



In its normal development the Hydatina egg never 

 goes through changes in which it is converted into an 

 aggregate of minute vesicles, or into a smaller number of 

 separate and larger spheres, such as occurs as a prelude 

 to the transformation of the egg-contents into ciliated In- 

 fusoria of this or that kind. 



Geological Society, March 8.— Dr. J. E. Mart. F.R.S., 

 president, in the chair. — Exhibits. — A series of photo- 

 graphic views illustrating the geological structure and 

 physical features of the mountains of Skye : .\. Harlcer. 

 The " CuUinan " diamond : Dr. F. H. Hatch. By means 

 of lantern slides from photographs the diamond was shown 

 from four points of view. The stone was a por- 

 tion (probably less than half) of a distorted octahedral 

 crystal. .\s it now existed, the stone was bounded by 

 portions of four original octahedral surfaces and by four 

 cleavage-planes. The former showed in places a slight 

 curvature, a mammillary structure, striations, and tri- 

 angular pittings, while the cleavage-surfaces were dis- 

 tinguished by greater regularity and smoothness. The 

 stone weighed 3024I carats. Its greatest linear dimension 

 was 4 inches. It was of remarkable purity for so large 

 a stone, approaching " blue-white " in colour. It was 

 found at the beginning of the present year, in the " yellow 

 ground " of the Premier Mine, at a depth of 18 feet below 

 the surface. The Premier Mine was a true "pipe," 

 situated on the farm of Elandsfontein, twenty miles north- 

 east of Pretoria (Transvaal). — Papers. — Observations on 

 some of the Loxonematid^, with descriptions of two new 

 species : Miss J. Donald. Shells having more convex 

 whorls, or less sigmoidal lines of growth than L. 

 sinuosum, cannot be left within the genus Loxonema. 

 The two new species described resemble the type in form 

 and in the sinuosity of the lines of growth ; but the whorls 

 are ornamented with spiral striae, two of which frequently 

 stand out and give the shell a banded appearance. — On 

 some Gasteropoda from the .Silurian rocks of Llangadock 

 (Caerniarthenshire) : Miss J. Donald. These fossils occur 

 almost entirely in the state of casts and moulds. Eleven 

 distinct forms have been made out, referable to seven 

 genera ; but only seven are sufficiently well preserved for 

 specific determination. Five of these are new, including 

 one described in the previous communication ; a new genus 

 is described, for the reception of EuompliaUis funatus. 



Chemical Society. March 15— Prof. W. A Tilden, F.R S., 

 president, in the chair. — It was announced that Prof. 

 Percy Frankland had presented to the society the eudio- 

 meter made and used by the late Sir Edward Frankland 

 for the analysis of ethyl in 1849 ; that Prof. Retzius, of 

 Stockholm, had presented an engraving of Berzelius ; and 

 that Mr. Oscar Guttmann had presented a bronze medal 

 struck in honour of Roger Bacon in Paris in 1818. The 

 council, on behalf of the society, had expressed its 

 thanks for these gifts. — The following papers were read : — 

 The velocitv of oxime formation in certain ketones : .\. W. 

 Stewart. The results of measurements of these velocities 

 are generally in agreement with those already found 

 for the addition of sodium hydrogen sulphite to ketonic 

 compounds, and since the two reactions belong to different 

 types, it seems probable that the hindrance to the re- 

 actions in the case of ketones containing many methyl 

 groups near the carbonyl is due to stereochemical and 

 not to purely chemical causes. — The ultra-violet absorp- 

 tion spectra of certain enol-keto-tautomerides, part ii. : 

 E. C. C. Baly and C. H. Desch. The results indicate 

 that the absorption band in these compounds is due to 

 change of linking taking place when one tautomeric form 

 passes into the other. It is possible to account for the 

 formation of the absorption bands by adopting the physical 



