2SO 



BAkDWICRE'S SCIENCE-GOSSIP. 



Trochus lineatus. — I found this species rather 

 common on the rocks at Herm this year and very 

 fine. One colony, however, had all the opercula much 

 deformed, and in one or two cases it was altogether 

 absent. Dr. Jeffreys, I believe, mentions a similar oc- 

 currence in his third vol. Mr. A. H. Cooke informs 

 me that he has found Buccinum undatum on the Welsh 

 coast, which had had the opercula, and part of the 

 animals pecked out by gulls. This would account for 

 total absence, but would it account for deformity or 

 depauperisation? I saw no peculiarity in the habitat 

 which would be likely to influence the growth of my 

 shells. Does the operculum of molluscs grow again 

 if removed ? — B. Tomlin, Pemb. Coll., Cam/'. 



BOTANY. 



Polysii'HOXIA fastigiata. — Accompanying the 

 plate of Polysiphonia fastigiata in the August number, 

 is a short statement purporting to describe the mode 

 of propagation. This is, however, somewhat mis- 

 leading, and I ask your permission to give those who 

 have relied only on Mr. Draper's note the proper 

 explanation. This plant bears three kinds of fruit, 

 generally on distinct plants. The tetraspores are 

 analogcus to buds, are asexual, and divide into four 

 parts (not more as stated) each of which is capable of 

 developing into a plant. The antheridia drawn in 

 the plate are the male fruit, and therefrom issue forth 

 minute rounded bodies, called antherozoids. These 

 bodies are washed near the female plants, on which is 

 a projection readily noticeable under the microscope. 

 From one part of this projection issues a very 

 minute hair-like and unjointed process called a 

 trichogyne, and to this trichogyne the antherozoids 

 become attached, and thus effect the fertilising act 

 which is followed by the complete development of the 

 female fruit, the cystocarp (Ceramidium of Harvey's 

 " Phycologia Britannica" ) containing the true spores. 

 This fruit is, according to all good botanists, the 

 basis of classification, and naturally the most im- 

 portant of all. But Mr. Draper has entirely passed this 

 over without remark. The cystocarp (or ceramidium) is 

 an even-shaped body, and the spores are arranged on 

 a placenta near the base, and at maturity issue forth 

 through an opening at the apex of the urn. The 

 antheridia on a properly-mounted specimen, form a 

 very beautiful object with the paraboloid and bino- 

 cular.— T. II. Buffham. 



Crocus NUDIFLORUS. — This autumnal crocus is 

 extremely abundant and quite wild in fields about 

 Prestwich clough, about four miles N. of Manchester, 

 and is also found in one or two situations on the 

 south side of that city. It also occurs in fields 

 sloping to the south near Singleton Brook, Kersal, 

 and overlooking Kersal Moor, about one mile nearer 

 Manchester than Prestwich. And again, it grows 



near Bury, about five miles farther north of this last- 

 mentioned locality. — y. Cosmo Melville. 



In the November number of the "Journal of 

 Botany," I have enumerated the species and varieties 

 of " Dianthus." As I am anxious to have an accurate 

 topography of its distribution in this country, might 

 I ask some of your readers to be so good as to forward 

 to me on cards, local records (if possible from recent 

 personal observation) of the indigenous British 

 species, viz. D. Armeria, deltoides (with var. glaucus) 

 ctcsius, and prolifer'i — Frederic N. Williams, F.G.S. 



Metastasis in Leaves. — The results of some 

 experiments on this subject by T. Sachs, which may 

 be found recorded in the "Journal of the Chemical 

 Society " for July, deserve notice here. It was 

 found that in the case of many plants starch was 

 found in the leaves in the evening, which disappeared 

 during the night, so that they contained none by 

 sunrise the next morning. It appears that, probably 

 owing to its conversion by a soluble ferment into 

 sugar, the starch is dissolved, passing into the stem. 

 It is said that during each hour of the day a square 

 metre of Helianthus' was found to gain '914 grm., 

 and of Cucurbita ■ 68 grm. of starch, while during each 

 hour cf the night they lost respectively '974 grm. 

 and '828 grm. 



GEOLOGY, &c. 



The Geology of Corstorpiiine Hill, near 

 Edinbro'. — I have been engaged in examining lately, 

 microscopically, a series of sections from the rock of 

 Corstorphine Hill, near Edinburgh. This rock is 

 described in all geological memoirs treating of the 

 district as diorite. All the specimens but one, I 

 found to have more or less the structure of diorite 

 (though not at all typical), this exceptional one was 

 nothing more nor less than a gabbro. This gabbro 

 was a crystalline aggregate of labradorite (with very 

 little oligoclase) diallage augite and a very little 

 hornblende. The other specimens were diorites, but 

 bore a distinct relationship to the gabbro. They 

 were crystalline aggregates of labradorite, oligoclase, 

 hornblende, and augite. Some of the latter mineral 

 altered to diallage. The rock of Corstorphine Hill, 

 therefore, as far as I have examined it, appears to be 

 quite as much a gabbro as a diorite. It shows, at any 

 rate, what I think has never been pointed out before, 

 the close relationship existing between diorite and 

 gabbro, and that one may pass into the other. — Alex, 

 yohnstone, F.G.S. 



The North Atlantic Basin. — The subject of 

 Mr. Melland Reade's presidential address to the 

 Liverpool Geological Society was " The North 

 Atlantic as a Geological Basin." A chart, embody- 

 ing the result of all the latest soundings, was exhibited 



