June 21, 1894] 



NA TURE 



17: 



Mohl's " Primordial Utricle." 



I SHOULD like to inquire, through the medium of NATURE, 

 whether the way in which botanists njw use Mohl's term 

 "primordial utricle" is strictly accurate ? In Sachs' " Lehr- 

 buch," and in the English translation, it is applied to the 

 parietal layer of protoplasm faMnA in plant cells which are old 

 enough to have a large central vacuole, and this practice is now 

 generally followed by English botanists. 



Now, in Henfrey's translation of Mohl's " Principles of the 

 Anatomy and Physiology of the Vegetable Cell," it appears to 

 be used in a different sense. On pp. 36-37 we have a descrip- 

 tion of tht young cells of plants, in which the " primordial 

 utricle " is spoken of as " a very thin granular iiwmhrane, " which 

 by appropriate methods becomes ^'' detached from the iusideoj the 

 ••oall" . . . "and consequently removes all the contents of the 

 cell, which are enclosed in this vesicle, from the wall of the 

 cell." (The italcs are mine.) After this Mohl briefly refers to 

 the nucleus, and then goes on to say that "the remainder of 

 the cell is more or less densely filled with an opake, viscid fluid 

 of a while colour, having granules intermingled with it, which 

 fluid I call protoplasm." 



Thus even \n young cells, Mohl recognises not only the proto- 

 plasm and the nucleus, but a " primordial utricle" also, and 

 save that he says it is granular, one might take it as the 

 equivalent of what we now speak of as the ectoplasm. 



Proceeding with his description, Mohl describes on p. 38, how 

 as plant cells become older, a large vacuole is gradually formed 

 in the interior of the protoplasm, which then becomes dififerently 

 distributed. In the result he tells us, " the protoplasm is then 

 accumulated at one side in the vicinity of the nucleus ; on the 

 other side /'/ coats the inside of the primordial utiicle." (Italics 

 again mine.) 



Thus in the older cells, as well as the younger, we have a clear 

 distinction drawn between the protoplasm an I the " primordial 

 utricle," a distinction which recent writers seem to ignore. 



It is possible, though scarcely likely, I think, that Ilenfrey has 

 not faithfully reproduced Mohfs conception of the " primordial 

 utricle," or it may be that my interpretation of the above pas- 

 sages is at fault. In any ca-,e, it would be an advantage to have 

 the opinions of our leading botanists on this point, as it i-i one 

 which, to my own knowledge, brings some perplexity to 

 students. Tho.mas Hick. 



Owens College, June 14. 



Hailstones at Cleveland, Ohio. 



A REMARKABLE hailstorm occurred at Cleveland, Ohio, on 

 the afternoon of Thursday, May 17, of a character 10 be 

 remembered but probably not repeated during the 1 resent genera- 

 tion. Larger hailstones are rarely seen than fell on that day, 

 and very likely tew, if any, people living in this part of the 

 country have ever witnessed a more severe bombardment. 



The air was intensely sultry up to twenty eight minutes past 

 three o'clock in the afternoon (sun time), when it commenced 

 to rain. Hailstones of moderate size rattled down in profusion, 

 and it soon appeared that an ordinary thunderstorm had begun. 

 At the east end of the city the wind increased rapidly in force, 

 and it grew very dark. Presently the hail became violent, and 

 for about twenty minutes the streets and lawns presented a 

 most animated appearance. The impact of the icy bullets 

 against the roofs of houses sounded like the rattle of musketry. 

 '1 he snow-white balls glistened upon the close-cropped lawns, 

 where they kept up a lively dance, and in the street were 

 shaitered against the lla;^s and paving stones. 



The stones, many of which were as large as billiard baIN, and 

 some of the size of goose eg..;s, weighed from one to five or six 

 ounces, and probably many that (ell were much heavier than 

 this. Their shape was very various, some being spheroidal, 

 others discoidal or exceedingly irregular. The accompanying 

 figures represent 10 some extent the forms of two stones which 

 lell on the .\delbcrt College lawn, and were picked up by some 

 of our students. 



A hailstone was found by Prof. K. P. Whitman to weigh 

 nearly an ounce and a half after it had melted considerably. 

 Its measurements were 2^ x 2j x i i inches. The surface was 

 fissured and raised into tubsrcles, while many others had an ex- 

 •^glierated mulberry appearance, suggesting a composite 

 structure. Sections of such stones showed, however, that they 

 were as a rule formed about a single nucleus, and were not the 

 result of the regelation of a number of se|)arale pellets. 



NO. 1286, VOL. 50] 



The specimen represented in Fig. I measured three inches 

 in length, two in breadth, and about one in thickness. There 

 were two opaque central masses, the larger of which contained 

 the original nucleus, while the smaller spot pro'ably represents 

 a stone which became welded to the larger and older one. 



A somewhat flattered, or discoidal form, which was very 

 common, presented a beautiful agate-bke core, embedded in a 

 clear mass. A section of one of the stones, which was sawn in 

 two, is shown in Fig. 2. Theie is a central ball of snow-ice, 



Fig. I. — Outline of hailstone two- 

 ttiirds natural size. Dimensions 

 3X2X1 inch. 



Fig 2. — Section of haibtone, two- 

 ttiirds natural size. 



and this is surrounded by alternating light and dark layers of 

 varying density, and by a very much thicker clear, outer 

 envelope, unshaded in the drawing, showing that the stone had 

 passed through at least two distinct regions of condensation. 

 There were also usually one or two thin superficial strata. 



A stone which was examined by ore of the observers at the 

 United Slates Signal Office, was 3J inches long, 3 inches wide, 

 2 inches thick, and measured \o\ inches in circumference. 

 Another, which fell near Board of Education Building on Euclid 

 I Avenue, was weighed and measured by Principal Then. H. 

 j Johnston. It was oval in shape and measured 3 ■ 2-5 x 2 75 

 inches, and weighed, after some melting, 4^ ounces. The sur- 

 face of this stone was deeply pitted as liv impact of warm rain- 

 drops. .\ second, brought in by one of Mr. Johnston's 

 pupils, weighed 5-5 ounces. It had a large pear-shaped snow- 

 iced centre. 



The hailstorm was restricted to a belt a few miles in length, 

 and formed a part of a general westerly stnrm, which was felt 

 in this region for four or five days. During the thunder and 

 hailstorm of May 17, the airpresure remained neaily consiant, 

 the temperature fell from 84° to about 64 F. .\t the begin- 

 ning of the storm the wind was south, and blowing at a rate of 

 ten miles an hour, and increased to a rate of only 24 miles an 

 hour. On the same day a destructive cyclone accurred at 

 Kunkle in the north-western part of the State, in which a 

 number of people lost their lives. 



Everything in glass exposed to the brunt of the storm, when 

 not of the strongest kind, was destroyed. Electric light globes, 

 photograph galleries, and greenhouses suii'ered most. Canvas 

 awnings were riddled. Flowers were cut down, and fruit and 

 shade trees badly injured in many places. Horses and oiher 

 animals, often too terrified to stir, winced under the slinging 

 shot which they could not avoid. A few cases occurred of per- 

 sons who were cut or stunned by the falling stones or glass. .\ 

 man at the Winton Bicycle Factory was struck in the head as 

 he stooped to pick up an unusually large stone, and was brought 

 into the workshop in an unconscious condition. The stone went 

 through his straw hat, and cut into his scalp. 



Francis H. HtKRicK. 



Adelbert College, Cleveland, Ohio. 



Finder Circles for Equatorials. 



O.N p. 64 of the current volume of Natire, I find a para- 

 graph on "Finder Circles for Equatorials," which demands 



