SCIENCE-GOSSIP. 



123 



CONDUCTED BY J. H. COOKE, F.L.S., F.G.S. 



To whom Notes, Articles and material relating to Microscopy, 

 and intended for Science-Gossip, are, in the first instance, 

 to be sent, addressed "/. H, Cooke, Edlestone, Battenhall 

 Road, Worcester." 



Recent Microscopical Research. — At a 

 recent meeting of the Royal Society of London, 

 Dr. Gait, of Glasgow University, communicated a 

 paper on " The Microscopical Appearances of the 

 Grains in the more commonly occurring Starches." 

 The paper was very detailed, and was illustrated 

 by many original photographs. At the Academy 

 of Science, France, MM. Bordas, Joulin and De 

 Racrkowski presented the results of their work on 

 " Micro-organisms of Turned Wines." The authors 

 have isolated and studied an organism which they 

 propose to call Bacillus roseus-vini. It takes its 

 name from the various colourings it assumes in 

 different cultivating media. 



How the Hydra Stings.— One of the most 

 common of the freshwater hydras found in England 

 is the interesting little Cordylophora. Its sting- 

 cells are contained in its skin, and though most 

 microscopists have heard of and seen them, there 

 are but few that know how they act. The common 

 idea is that the animal uncoils the stings when it 

 likes, and pierces its prey with them, the stings 

 remaining attached to its arms. That is a mistake. 

 There is a kind of trigger projecting a little way 

 from the skin. When this is pressed by the arm 

 of the animal squeezing its prey it releases the 

 spring, which uncoils like a flash and becomes 

 perfectly straight and rigid. The sting, which has a 

 little round head to it, comes right out of the hydra, 

 and sticks into its prey like a tiny pin with the 

 head outermost. Hundreds of these atomic pins 

 are shot out by the hydra against, say, a water- 

 flea, and by the time it is dead, the poor little 

 Daphnia looks like a round pin-cushion full of pins. 



The Food of Uropoda. — At a recent meeting 

 of theLinnean Society, Surgeon-Captain Cummins, 

 F.L.S., read a paper on the above subject. The 

 nature of the food of these mites, which belong to 

 a highly specialized genus of the Gamasinae, had 

 long been a puzzle even to those who have paid 

 particular attention to their organization. From 

 careful experiments and observation, the author of 

 the paper had come to the conclusion that amongst 

 the organisms on which the Uropoda live were 

 many species of bacilli, including the potato 

 bacillus and the earth bacillus. Wild yeast-cells 

 were rapidly devoured, as also were Micrococci. 

 He had little doubt that they consumed thegonidia 

 of fungi, for species of Penicillium and Mucor never 

 appeared in the boxes which contained mites in 

 large numbers, otherwise they were commonly 

 present. Mr. A. D. Michael, in criticising the 

 paper, pointed out the distinguishing characters of 

 the Uropoda as compared with others of the 

 Gamasinae, and especially the peculiar form of the 

 mandibles, which suggested a different mode of 

 feeding to that adopted by other mites. 



Microscopical Directory. — Readers of Science- 

 Gossip who may desire to have their names 

 included in the new Microscopical Directory for 

 189S are requested to forward their names and 

 addresses to "The Journal of Applied Microscopy," 

 Rochester, N.Y. It is also advisable to state the 

 special line of microscopical work engaged in, 

 whether in possession of a collection, and if 

 exchanges are desired. The insertion is made free 

 of charge. 



What is a Sponge ?— Sponges are very in- 

 teresting and puzzling to the zoologist who makes 

 classification his hobby. Is a sponge " an animal "? 

 One of the Metazoa? Or does it belong to the 

 Protozoa? — in which case it is not an animal, but 

 is only a huge " colony " of unicellular " animals." 

 There is a good deal to be said on both sides. In 

 its canals may be seen organisms identical with 

 the collared monads, which are apparently indi- 

 visible from the animals. This goes to show that 

 it is merely an overgrown colony of monads. It 

 has a skeleton of spicules not unlike the spicules of 

 gorgonia, and, in the autumn, it produces a kind of 

 " winter egg," which has a hard shell. This 

 makes one think it " an animal," and belonging to 

 the Metazoa. In favour of this view, Mr. H. M. J. 

 Underhill has suggested that the collared monads 

 in the canals, without which no sponge is ever 

 found, may really be individual monads living in 

 partnership with the higher animal : in other 

 words, that we have here an excellent example of 

 symbiosis. 



Manchester Microscopical Society. — We are 

 in receipt of the " Transactions and Annual Report ' ' 

 of this Society for the year 1S9S, and are pleased to 

 see that the membership roll is so large and that 

 the society maintains its reputation for solid and 

 valuable work. All the articles in this its latest 

 volume are of a biological character, a fact that is 

 probably due in a measure to the benign influence 

 exerted by the late president, Prof. A. Milnes 

 Marshall. Microscopical manipulation and tech- 

 nique are essentials to good work, but to make 

 them the one object of a society's existence serves 

 no useful purpose. On the contrary, it absorbs 

 much energy and enthusiasm that might be better 

 employed. The Manchester society sets an exam- 

 ple that its metropolitan confreres might follow 

 with advantage. The contributions to the present 

 number include articles on " Adaptations in 

 Plants," by Prof. F. E. Weiss; "The Functions 

 and Structure of Leaves," by C. Turner; "Natural 

 Selection in the Lepidoptera," by M. L. Sykes ; 

 " The Influence of Light and Temperature on 

 Vegetation," by J. Axon. 



Study of Lichen Structures. — For the study 

 of lichen structures, Professor G. J. Pierce has been 

 most successful with a concentrated (or saturated) 

 solution of corrosive sublimate in thirty - five 

 per cent, alcohol. This he uses hot, and so secures 

 very rapid penetration, killing and fixing, during 

 and after which no contraction takes place. If the 

 lichen material is air-dry, but still alive, it should 

 be thoroughly wetted and kept moist for two or three 

 days, and then small pieces only should be put into 

 the hot fixing agent, in which they will promptly 

 sink to the bottom, where they may be left for a 

 suitable length of time, from five minutes to a 

 half-an-hour. Slow dehydration in the alcohols 

 using five or six grades and comparatively large 

 volumes in proportion to the size of the objects 

 will secure the removal of the last traces of corro- 

 sive sublimate. 



