il A 11 J ) \ V 1 C K E ' S S C I E K C £ - G O S S I P . 



135 



extended. And should a water-flea come within 

 the reach of the tentacles, they readily seize it and 



Fig. 101. Hydra after cutting. 



draw it to the mouth of the polyp. The flea will 

 struggle M'itli the polyp, and will drag it about at 



Fig. 102. Hydra tiiree hours after cnttins 



the bottom of the glass, as the Hydra has no foot - 

 stalk or sucker to hold on with, being cut asunder. 

 But, liowever, it holds fast on the flea, and finally 

 absorbs it. The foot-part of the severed Hydra 

 still continues to hold on to the plant or side of the 

 glass where it was fixed when it was cut in two ; 

 and, stretching out its full length, patiently waits 

 until a new head and tentacles are formed, before it 

 can catch its prey to satisfy its appetite. I have 

 figured the forms of some of the polyps three hours 

 after being cut in two. I have seen the tentacles 

 reproduced in a few hours after the operation, sufii- 

 cieut to enable the Hydra to catch and absorb the 

 water-flea. In one of my glasses are several Hydras 

 the results of my cutting two to pieces ; one I cut 

 in two, the other I cut into several pieces, and they 

 are all restored to perfect animals. 



James Fullagak. 



MICEOSCOPY. 



List of rouMS ix Mollek's Diatomaceex 

 PnoBE Platte. — Triceratium Eavus, Pinnularia 

 nobilis, Navicula Lyra, Navicula Lyra, var., Pinnu- 

 laria interrupta, 1-inch objective ; Stauroneis Phce- 

 niceiiterou, Grammatophora marina, Pleurosig a 

 Balticam, f -inch ditto ; Pleurosigma acuminatum, 

 Pleurosigma angulatum, ^-inch ditto ; Pleurosigma 

 fasciola, Grammatophora subtilissima, Surirella 

 gemma, Nitzschia sigmoidea, -g-inch ditto ; Cyma- 

 topleura elliptica ; Navicula crassinervis, I'^-inch 

 ditto ; Nitzschia curvuhn, ^-inch ditto ; Amphipleura 

 pellucida, yViiich ditto. The above is a copy of 

 Mollcr's list, with the powers usually necessary to 

 resolve the forms'; but, being mounted in balsam, 

 the striae are much more difiicult to resolve than 

 when mounted dry. KUzschia curvula (Smith) 

 of lists is not that form, but N. sigma of Smith, 

 The former is not a Nitzschia, but a Surkella,— the 

 S. intermedia of Dr. Lewis. The illuminating ray 

 requires to be more or less oblique in all cases 

 where the ofcj;;ctive is less than ^. 



Fui^GoiD GiiowTiis ON Leayes of Coleus. — 

 A paper was read before the Royal Microscopical 

 Society, by Mr. H. J. Slack, P.G.S., &c., on the 

 supposed fungus on Coleus leaves. A microscopic 

 examination of the leaves revealed certain peculiar 

 appearances on their under surfaces, which had 

 hitherto been attributed to fungoid growths. When 

 a leaf of a Coleus is examined by means of a lens, a 

 number of globular bodies of a beautiful yellow tint, 

 highly translucent and refractive, and the majority 

 of them marked with a cross like that impressed on 

 the well-known cross-bun, mny be detected. These 

 bodies are pretty uniformly distributed, without 

 any regard to the variegations of the leaf-colouring 

 matter. The colours of these bodies, when healthy 



