GS 



HARDWICKE'S SCIENCE-GOSSIP. 



[March 1, 1S70. 



MICROSCOPY-. 



My Tank. — In your number for December last 

 you were good enough to insert a paragraph from 

 me respecting the appearance of Melicertians in 

 the dendritic form; these have since then disap- 

 peared, aud floscules of a small kind, but in immense 

 numbers, have taken their place, and have been in- 

 creasing in my tank through the winter. Most of 

 these have one or two eggs, and are continually 

 multiplying. I may mention that I have also several 

 species of the (Ecistes, a tube rotifer mentioned by 

 Mr. Slack in " Pond Life." In the same water I 

 find numerous fine Stentors, also Vorticellse, Amceba, 

 &c. The water of my tank has not been changed 

 for over six months, and the weed, principally 

 Myriophyllus, was put in at the end of last summer, 

 but the floscules appear to me to congregate princi- 

 pally on the alga?, which grow only far too rapidly. 

 — George II. Fryer. 



Muscular Motion. — Whilst examining the 

 larva of some small beetle which is very common in 

 ruuning water, I had an opportunity of observing 

 the mode in which muscular motion is propagated. 

 The skin of the larva is so transparent .that the 

 action of the muscular bundles moving the feet was 

 seen with the greatest ease. At every movement 

 of the foot, I could sec that each muscular fibre was 

 not contracted simultaneously ; but the beginning 

 of each fibre became swollen; then the swelling 

 passed along the fibre in the form of a wave to the 

 other end (fig. G6). As each filrilla seems to con- 



Fig;. 66. 



sist of a number of cells connected together in a 

 transparent sheath, the muscular motion would 

 appear to arise from the lateral expansion, and con- 

 sequent longitudinal contraction of each consecutive 

 cell. And the propagation of force through the 

 muscular fibres seems, therefore, to follow the same 

 law, and to produce similar effects as in other media, 

 —J. S. Tute. 



Eoraminifera in Elint— Having made an ex- 

 cellent collection of Foraminifera from some chalk 

 taken from the cavity in the interior of a flint 

 nodule, I wish to bring it before the notice of your 

 subscribers. All things relating to the formation of 

 chalk are now of especial interest, in consequence 



of the identity of forms recently found in the deep 

 Atlantic dredgings with those of the fossil animal- 

 cule of the chalk strata. In my collection, the 

 shells are beautifully perfect, iu consequence of 

 their having been enclosed in the flint cavity ; but 

 the fact of their being in that position only proves 

 that the flint, when a sponge, was surrounded by 

 myriads of like forms, and that portion in the in- 

 terior, when the animal perished aud became slowly 

 silicified, has been preserved from all pressure ; and 

 the forms now present themselves as beautiful and as 

 perfect as an hour after their death. The substauce 

 taken from the flint was like the surrounding chalk, 

 excepting that it was of very much less specific 

 gravity : it is composed entirely of Foraminifera, spi- 

 cules, and a few Poly cist ilia. Theformsmost plentiful 

 are the Globkjerina and Rotalia, exactly identical 

 with those of the deep-sea dredgings ; so that it is a 

 fair assumption that strata similar to those of the 

 Hampshire chalk are now in process of formation 

 at the bottom of the Atlantic. I have a small 

 quantity of the chalk, which I shall be happy to 

 share out amongst any who care to see it. — Arthur 

 Angell, Jan., Secretary of the Winchester and Hants 

 Literary and Scientific Society. 



Starch of Calarar Bean {Physostigma vene- 

 noswm).—We have received from Mr. Edmund 

 Wheeler, of Holloway, a slide of this starch, pre- 

 pared by him for sale, which is remarkable for its 

 size, it being equal to that of " Tous-les-mois." 



Fig. 67. Calabar Bean Starch, x 320. 



The characteristic central slit, or hilum, is that of 

 the bean tribe, by which, as well as by its polariza- 

 tion, it may easily be distinguished from any other 

 known starch. It will be quite an acquisition to the 

 microscopical cabinet. 



Rhododendron Scales.— Any one possessing a 

 plant of Rhododendron Dalhousii will find on the 

 under side of its leaves interesting scales somewhat 

 similar to those of Ehcagmts ; but whereas those of 

 Mlceagnus appear in the microscope ragged at the 

 margin, those of R. Dalhousii present a more un- 

 broken circumference. — W. Hambrough. 



Rivulet Moth.— It .may interest some readers 

 to know that I captured a specimen of the Rivulet 

 Moth {Emmelesia affinitatd) at l'artick, near Glas- 

 gow, last season : it was supposed to be unknown 

 in Scotland or Ireland. — John M. Campbell. 



