66 



HARDWICKE'S SCIENCE-GOSSIP. 



NOTE ON CLADOSPORIUM DEPRESSUM. 



M 



Y friend Mr. Soppitt, of Saltaire, sent me last 

 month a few leaves of Angelica sylvestris, on 

 which were growing perithecia of Splnzrella ostruthii, 

 Fr. These perithecia are remarkable, as being ag- 

 gregated on small angular greyish spots which are dis- 

 tinctly limited by the venules of the leaf. It appears 

 that the mycelium which has begun to grow within 

 the parenchyma of any intervenular area is unable to 

 penetrate the vascular bundles of the venules, and 

 is consequently confined to the area within which it 

 originated. The perithecia of this species are almost 

 constantly barren in this country, and it becomes a 



Fig. 50. — One of the serrations of the leaf of Angelica sylvestris, 

 with three intervenular patches of Spluzrella Ostruthii. 



Fig. 51. — Tuft of fiocci and spores of Cladosporium depressum. 



question how the fungus is propagated. I was pleased 

 to see one answer to this query in the small tufts of 

 dematoid mould which grew on and round the bases 

 of many of the perithecia. This I found to be Clado- 

 sporium depression, B. and Br. It is well known that 

 the perithecia of many sphneriaceous fungi are adorned 

 in this way, as is so beautifully represented in the 

 plates of Tulasne's " Selecta Fungorum Carpologia ;" 

 and in point of fact most of the fungi contained in the 

 suborder Dematici, like those in the Sphreronemei 

 and others, will be found to be mere modes of repro- 

 duction of species included in other orders. For 

 instance, the common Cladosporium hcrbarum is 

 known to be only the conidial stage of Sphccreia her- 

 lartim, and in the same way it must be admitted that 



Cladosporium depressum" is the conidial phase of 

 Spharella ostruthii, and the means whereby the fungus 

 propagates itself during the summer, although it must 

 have some other mode of continuing its existence 

 through the winter months. 



W. B. Grove, B.A. 



MICROSCOPY. 



Manchester Microscopical Society. — The 

 annual soiree of this flourishing society was held in 

 the Athenaeum, Manchester, on Saturday evening, 

 February 24th, and was attended by a large company 

 of ladies and gentlemen. There was a capital show 

 of microscopes and microscopic objects, living and 

 dead. During the evening a lecture was delivered 

 by Dr. J. E. Taylor, editor of Science-Gossip, on 

 " Flowers and Fruits, and their Relation to Insects 

 and Birds." 



Anatomical Objects. — We have received from 

 Mr. R. G. Mason a series of cheap and very effective 

 sections, illustrating the normal anatomy of the 

 mammalian lung, with full instructions for mounting, 

 &c. These cannot fail to be instructive to a young 

 beginner. 



Meteorites. — Some time ago, I bought one of 

 the slides showing moving bubbles, named by H. M. 

 (page 276), and compared! it carefully with several 

 genuine slides of meteorites, which in no respect does 

 it resemble. I should think it is built up chiefly of 

 waterworn quartz grains (with here and there a 

 grain of orthoclase and (?) Microline) cemented 

 together by an iron-oxide of some kind whose precise 

 constituents can be determined by analysis only; 

 probably it is limonite. M. Hensoldt is a stranger 

 to me, but from all I learn, he would be the last man 

 intentionally to .mislead his fellow-workers, and he 

 could settle the doubt by obtaining an analysis from 

 a recognised authority. Meanwhile will H. M. 

 submit his slides to a competent judge of meteorites 

 and let your readers know the result ? — T., Yorkshire 

 College. 



Magnifying Measurements. — E. A. C. H. has 

 made some mistake, either in the power of his 

 objective and ocular, or in making his measurements. 

 A 1 -in. objective (assuming, as is usually done by 

 English opticians, that the distance necessary for 

 perfect vision is 10 inches) magnifies 10 diameters. 

 Ross's, Beck's, and Powell and Lealand's B. ocular, 

 magnifies 7J diameters, giving an amplification of 75 

 diameters ; that is, supposing that the length of the 

 body is 10 inches, but if, as is often the case with 

 continental instruments, it is only 8 inches, or even 

 less, the amplification would of course be only 60. 

 But as E. A. C. H. says his objective and ocular only 

 magnifies 33^ diameters, the length of the body of his 



