HARDWICKE'S SCIENCE-GOSSIP. 



ij 



The Quekett Microscopical Club. — The last 

 number of this well-known journal (edited by Mr. H. 

 Hailes) contains the following papers and notes : 

 " On a New Form of Live-Box," by C. G. Dunning ; 

 " On Spongilla fragilis found in the Thames," by B. 

 W. Priest; "On the Interpretation of Microscopic 

 Images with High Powers," by E. M. Nelson ; " On 

 a new species of Gamasus" by A. D. Michael ; " On 

 the Finer Structure of certain Diatoms," by E. M. 

 Nelson and G. C. Karop ; also a list of the objects 

 obtained in the excursions during the year 1885, etc. 



Removing Cuticles. — Will some reader have 

 the kindness to say how the cuticles of leaves such as 

 Deutzia, stinging-nettle, and others containing inte- 

 resting hairs may be removed? Boiling in water has 

 been recommended, but I am not successful with that 

 plan. The difficulty seems to be the removal rather 

 than the loosening of the cuticle. — //. 



New and Interesting Slides. — We have re- 

 ceived from , Mr. Fred Enock Nos. 2 and 3 

 of his "Entomological Sketches" — the "fairy 

 fly" {Anagrus incarnatus), and the head of a 

 ground bee [Colleles Daviesiana). It is a capital 

 method of studying entomological anatomy, to have 

 a pictorial detail and verbal description together 

 with the actual objects themselves mounted as few 

 besides Mr. Enock can. Mr. H. Vial, Crediton, has 

 also sent us three of his now well-known anatomical 

 sections of the lower lip of monkey, kidney of 

 monkey, and spleen of ditto, all injected with car- 

 mine. To Mr. Moss our thanks are also due for a 

 neatly mounted specimen of the rhizopod Clathrulimi 

 clegans, new to England, which he describes in our 

 present number. 



The June number of the "Journal of the Royal 

 Microscopical Society " is also to hand, containing 

 the following papers: "The Life History of an 

 Acarus, one stage whereof is known as Lapidophorus 

 fa/pa; Kramer ; and on an Unrecorded Species of 

 Disparipes," by A. D. Michael; "On Micrococcus 

 Pasteuri" by Dr. G. M. Sternberg; and on "A 

 new Polarising Prism," by C. D. Ahrens. All the 

 papers are illustrated. 



ZOOLOGY. 



Pathological Conditions in the Mollusca. — 

 If I understand the conclusion of Mr. Cockerell's 

 article on p. 98 aright, viz., that a pathological con- 

 dition may be transmitted, and so become congenital, 

 and afterwards so normal as to justify the formation 

 of a new species, as he illustrates, I would point out 

 that such a kind of transmission does not always 

 obtain, and consequently must be considered more or 

 less as an accidental occurrence. In cases of albino 

 {Helix grisea, Linn.), Dr. Martinati observed that 

 their produce were normal (E. de Betta, "Moll. prov. 



Veron," pp. 60, 61). Hartmann (" Gastropoden d. 

 Schweiz") explains albinism in shells to be due to 

 moisture, cold, and want of sunshine, and there 

 seems every reason to believe that they form factors 

 in its production. — J. W. Williams. 



Aerial Habits of Euglen^e. — The subjoined 

 extract from a memoir by Dr. D. D. Cunningham, of 

 Calcutta, on " The Relation of Cholera to Schizomy- 

 cete Organisms," will interest students of the Infusoria 

 and the Bacilli : "At almost any season many of the 

 tanks in and around Calcutta are more or less covered 

 by a scum of Euglence, which is of a bright brick-red 

 colour in the morning, of a vivid green in the evening, 

 and which is much less conspicuous and defined 

 during the day than it is from sunset to sunrise. 

 These variations in its characters are dependent on 

 recurrent periodic changes in the condition of the 

 component Euglence. The definition, and specially 

 the dry dusty aspect of the scum in the evening and 

 early morning, are due to the fact, that at these times 

 the vast majority of the Euglence are aerial, and not 

 aquatic organisms, the cells containing the then 

 encysted and passive protoplasts, being raised in 

 various degrees above the surface of the water, and 

 in the majority of cases being entirely removed from 

 contact with it, and projecting freely into the air. 

 The relative inconspicuousness of it during the day is, 

 on the other hand, due to the fact, that they are then 

 submerged, and swimming free in the water. The 

 changes in colour are dependent on alterations in the 

 relative amounts of red oily colouring matter, and 

 specially in alterations in its distribution within the 

 bodies of the protoplasts. The scum is not, however, 

 solely composed of Euglenas, but, on the contrary, 

 contains masses of the empty cysts and stems with 

 dilated bases belonging to previous cycles of the 

 encysted condition of the organisms. Bright, dry 

 weather tends to induce constantly increasing thick- 

 ness in this scum, due to the fact, that under such 

 circumstances the normal cycle of developmental 

 changes of form goes on recurring with unbroken 

 regularity, and that accordingly, quite apart from 

 coincident processes of multiplication connected with 

 the encysted condition of the organisms, there is 

 necessarily a constantly recurrent addition of incre- 

 ments of dead matter in the form of empty cysts and 

 stems. Heavy downfalls of rain, on the other hand, 

 tend to cause it to disappear, due to the fact that 

 they both break up the sheets of empty cysts and 

 stems, and by driving the Euglense down into the 

 water, tend to prevent their normal assumption of an 

 aerial habit. So long, however, as conditions remain 

 favourable to the regular periodic succession of the 

 diurnal and nocturnal phases in the life-history of 

 the Euglence, a steady increase in the scum goes on. 

 Any scum of this nature, composed in considerable 

 proportion of dead organic materials, affords a favour- 

 able site for the development of both saprophytic 



