2l6 



NA TURE 



I July 3> 1884 



having been a shallow-water deposit was "based exclusively on 

 the present habits of the very few genera of Mollusca that 

 have survived from the Chalk period, and seems quite in contra- 

 diction to the far more important groups, the Sponges, Echino- 

 dermata, and the minute organisms of which the formation is 

 so largely compo ed, while no opinion has yet found its way into 

 the hands of geologists regarding the depth of water indicated 

 by the Crustacea and the fishes of the Chalk." Mr. Gardner 

 appears to have overlooked that passage in my Address to the 

 Biological Section of the British Association (to which he refers 

 in his letter), wh rein I added, "Mr. Woodward tells me that 

 the Chalk Crustacea are shall w-water forms." Dr. Wood- 

 ward is certainly no mean authority on fossil Crustacea. As to 

 the surviving genera of Chalk Mollusca being "very few" in 

 number, I would refer him and my readers to the long list 

 of genera given in my Address, which was furnished by our 

 great palaeontologist, Mr. Etheridge, and to the exclusively 

 littoral habits of some of those genera. And with respect to 

 the Sprnges, Echinodermata, and minute organisms being "far 

 more important groups "than the Mollusca, I must leave that 

 question to naturalists in general. Sponges (silicious as v ell as 

 horny or ceratose), and Echinoderms are notoriously not restricted 

 to deep water. Quite the contrary. They live at every depth 

 from the shore between tide-marks to the abyssal and benthal 

 zones. The "minute organisms " which enter so largely into the 

 composition of the Chalk, for the most part, if not entirely, 

 inhabit the surface of the sea. J. G\VYN Jeffreys 



June 30 



Protoplasmic Continuity in Plants 

 In he very interesting article on " The Continuity of the Pro- 

 toplasm through the walls of Vegetable Cells," which appeared 

 in Nature of June 19 (p. 182), reference is made to the doubt 

 which still exists as to "whether the con'inuity is maintained 

 from the earliest stages, or is established later." This point is so 

 important in its physiological bearings, as the article goes on to 

 show, that I may, perhaps, be allowed to state tha^, with regard 

 to one group of plants, the question appears to be already settled. 

 I allude to the Red Sea-weeds or the Floridetz. The writer of 

 the article makes no mention of these plants, but, as I have 

 described elsewhere (see British Association Report, 1S83, p. 547, 

 and Journal of Botany, February pnd March 1884), many of 

 them exhibit a very notable system of intercellular connections, 

 which, extending over the whole thallu«, renders the protoplasm 

 practically continuous from the base of the frond to the extremities 

 of its furthest ramifications. Now in these cases the continuity 

 is certainly maintained from the first, and is due to the mode of 

 cell division by which the lhallus is built up. Into the details of 

 this there is no need to enter further than to say that, when the 

 protoplasmic body of a cell divides into two or more portions, 

 these do not become completely separated from one another, but 

 remain connected inter se by strands of protoplasmic material, 

 which grow in thickness with the growth of the cells, and thus 

 maintain the continuity from the earliest stages onward. So far, 

 then, as concerns the F/oridetr, I venture to think the physiological 

 import of the phenomena of continuity may be safely discussed 

 on the assumption of its existence ab in t 0. What that import 

 may be I do not propose to consider, my object being simply to 

 point to the Floridetz as throwing valuable light on the whole 

 subject, and giving some support to the view that "the entire 

 plant or organ is practically one whole — one mass of protoplasm 

 cut up into chambers which communicate with one another, and 

 bounded by a membrane on the exterior." Thomas Hick 



Aseismatic Tables for Mitigating Earthquake Shocks 



With respect to Mr. C. A. Stevenson's letter in your last 

 issue (p. 193), I may state that my information was obtained 

 from Mr. R. H. Brunton's paper on '■The Japan Lights" in 

 Proc. Inst. Civ. Eng , vol. xlvii., pp. 6-8, 35, and from the 

 communicaiion by Messrs. Stevenson in the "Discus-ion" on 

 that paper (pp. 26-29). The results referred to by Mr. Steven- 

 son have, perhaps, been obtai ed since this paper was read 

 (November 14, 1876). W. roPLEY 



28, Jermyn Street, London, June 27 



Black Rain 

 A REMARKABLE shower of black rain fell here and in the 

 neighbourhood last Sunday, the 22nd in-,1. The forenoon had 



been fine, though somewhat hazy, but about 3.30 p.m. heavy 

 cumuli formed to north and north-west. Gradually a dense 

 mass of cloud and haze came from the northward, presenting a 

 lurid, threatening aspect, and it become so dark that one could 

 not read a book indoors. At 4.30 rain began to fall, at 

 first a few drops, and soon after a heavy downpour. Whea 

 this commenced I noticed a number of black objects floating in 

 the air, which I at first took to be flies or winged ants, but they 

 rapidly increased in number, and on looking at them more 

 closely I found them to be particles of soot, on an average about 

 the size of the common fly. Their number was so great that, 

 it appeared for ten minutes to be snowing black, the descent of 

 the blacks being slow, like that of snowflakes. After it had 

 rained heavily for fifteen minutes, these "blacks" ceased and 

 the air became lighter, but the rain continued for another hour, 

 and altogether I measured '30 inches in my gauge. I find on 

 inquiry that this black rain was noticed in the whole neighbour- 

 hood — at least four miles to the north-east and two miles to 

 westward, hence it cannot have been due to local chimneys. As 

 far as I can ascertain, the shower was entirely local ; it seems 

 to have followed a narrow course from north to south only a few 

 miles wide, and did not extend to either Eastbourne or Hastings. 

 Fletching, Sussex, June 24 W. J. Treuti.er 



A Cannibal Snake 



Rather a strange occurrence came recently before my notice, 

 and thinking perhaps you might care to insert it in your columns, 

 I send you the facts of the circumstance. A few days since, 

 towards evening, I killed a snake just close behind my house ; it 

 measured about a yard and a half in length, was one of the most 

 deadly of the numerous kinds of snakes found in Java, and bears 

 the name of " Oelar belang." On examining it later I found 

 what I thought to be the tail of another small snake protruding 

 from its mouth, but on pulling it out I was greatly surprised to 

 discover that it was really a snake of the same species, and of 

 almost the same length. There was certainly not more than 

 three inches' difference in the length of the two snakes, and at 

 the time I killed the outside snake only about an inch and a 

 half or two inches of the tail of the one he had swallowed pro- 

 truded from his mouth. The outside snake was of course con- 

 siderably the thicker of the two, but this may be attributed to 

 his having swollen after, or rather during, his tremendous meal. 

 The natives here say that the two snakes must have been fighting, 

 the victor afterwards swallowing his opponent. I should be 

 pleased to know whether such an instance has ever before been 

 brought before your notice, or whether it is really an uncommon 

 case. Edwin H. Evans 



Soemedang, Java, May 20 



Peronospora infestans 



On the 22nd inst. I observed that this fungus had appeared 

 on the haulm of the potato crop in one or two places in my 

 garden in this city. On examining to-day a potato crop in another 

 garden a mile distant from mine, I perceived that that crop was 

 likewise affected. Considering the dryness of the spring weather, 

 the appearance of the disease is remarkable. According to my 

 observation, the attack of the mould is a month earlier than 

 usual. It may be added that hereabouts, this season, blight of 

 all kinds is prevalent, while last year was blight free. Inclosed 

 is a specimen of diseased haulm. J. Li,. BOZWARD 



Worcester, June 24 



KEPHIR 



IN No. 10 of the Journal of the Berlin Chemical Society 

 for June 23 is a communication on this substance by 

 M. Struve of Tiflis, continued from a previous note in 

 the same journal of February 25. 



Kephir is a form of fermented milk which has been 

 prepared and in use amongst the inhabitants of the 

 Northern Caucasus for a great length of time, and occupies 

 with them a similar position as an article of diet and t 

 medicine to that of kumis in the south-eastern steppes of 

 Russia. 



Kumis was first brought into notice in 17S4, and has 

 since then been pretty fully investigated and taken a 

 definite position, but' kephir has only been generally' 



