SCIENCE-GOSSIP. 



of the ideal object for the purpose, is, for a first- 

 class four-tenth inch, the black dots of Pleurosigma 

 angulatum in balsam, and perhaps, and imperfectly, 

 the secondary structure of A rachnoidiscus ehrcnbergii ; 

 for a one-fifth inch the longitudinal lines of 

 Surirellagemma, and the secondary structure, 

 Isthmia nervosa, with the postage-stamp fracture ; 

 for a one-eighth inch, or for higher powers up to 

 the one-twelfth, the dotted secondaries of Cras- 

 pedodiscus elcgans in certain conditions. 



Fruiting-time of Volvox. — What is the usual 

 season of the year during which Volvox can be 

 found in fruit ? In certain books which I have 

 referred to for information on the matter there are 

 statements to the effect that during the summer 

 Volvox is reproduced in the vegetative manner only, 

 but in the autumn sexual organs may be formed. 

 Is the autumn the proper season to find this alga 

 in fruit ? I do not know whether my experience is 

 exceptional, but towards the end of June, Volvox 

 minor, living in one of my aquaria, was bearing ripe 

 oospores, and examination of a gathering of Volvox, 

 made during an outing several days ago, showed 

 both Volvox minor and V. globator to be bearing 

 abundant fruit. — C. E. Britton, 189, Beresford Street, 

 Camberwell, S.E. ; August, 1897. 



Flour Weevils. — These little pests are more 

 or less familiar to most of us owing to their marked 



Pyralis farinalis. 



a, Egg mass ; b, Eggs — more enlarged ; c, Egg showing 



embryo within; d, larva, dorsal view; e, Pupa. All 



enlarged. — After F. H. Chittenden. 



proclivities for the flour-barrel and other receptacles 

 in which farinaceous matter is stored. Mr. F. H. 

 Chittenden, in his " Farmers' Bulletin," No. 45, 

 tells us that owing to the minuteness of size and 

 the paleness of colour of the eggs and larvae of 

 these beetles, they often escape notice ; being 

 overlooked, these mature, and in due course the 

 flour is ruined ; for when the insects have time to 

 propagate, they soon convert the flour into a grey, 

 useless mass. The accompanying illustration shows 

 it at various stages of the growth of the meal moth, 

 Pyralis farinalis, in its three earlier stages. 



Life-History of the Water-Mites. — The 

 "Journal of the Quekett Microscopical Club" for 

 the current quarter contains some interesting notes, 

 by Mr. C. D. Soar, on Hydrachnidae, in the course 

 of which he records his personal observations 

 regarding the life-histories of the water-mites. The 

 time that elapsed between the laying of the eggs 

 and their development varied very much in different 

 genera; for instance, Arrcnurus caudatus (De Geer) 

 took twenty-four days, Ncsoea carnea (Koch) twelve 

 days, Diplodontus despiciens (Mull) twelve days, 

 Eylais extendens (Mull) thirty-eight days, Hydradroma 



rubra (De Geer) twenty-six days. These develop- 

 ments took place at different dates from March to 

 October, so it will be interesting to note if these 

 great differences are peculiar to the species or to 

 the time of the year. Mr. Soar's observations are 

 rendered all the more valuable by the fact that so 

 little has hitherto been done in this subject. In 

 the same journal Mr. W. B. Stokes explains the 

 origin and behaviour of multiple images in mirrors, 

 a phenomenon which most microscopists have 

 noticed, but which few have sought to remedy or 

 to explain. 



Distribution of Pelagic Foraminifera. — 

 Students of the Foraminifera should read Dr. John 

 Murray's article on " The Distribution of the 

 Pelagic Foraminifera at the Surface and on the 

 Floor of the Ocean," which appears in the July 

 number of "Natural Science." 



The Earth's Development. — To the micro- 

 scopist and biologist the origin of life must long 

 continue a tempting subject for speculation. A 

 Philadelphia investigator, Mr. Charles Morris, 

 contends that the conditions favouring the develop- 

 ment of organic material were transitory, and no 

 longer exist, such material having arisen from a 

 vitally active stage of inorganic chemistry. There 

 must have been a time in the earth's history, he 

 reasons, when chemical inactivity prevailed on 

 account of high temperature and unfavourable 

 chemical conditions. Chemical activity arose and 

 increased as the heated ocean was formed, and 

 changed the first simple substances into compounds 

 of gradually growing variety and volume. Many 

 resulting complex minerals were probably deposited 

 as rock formations. The ocean having deepened 

 and freed itself from foreign material, inorganic 

 chemical activity gradually diminished, until it has 

 now practically ceased, oxidation having reduced 

 nearly all substances to a state of chemical fixity. 

 With the cooling of the primeval ocean, and the 

 increase of sunshine, came organic chemical 

 activity. The material had been prepared in 

 air and water, and may have had its origin in an 

 early reaction between carbon-dioxide and the 

 elements of water, yielding hydrocarbons, and subse- 

 quently, between these and nitrogen, yielding the far 

 more complex albuminous compounds. The com- 

 plexity of mineral molecules doubtless increased 

 under conditions restraining the activity of oxygen. 

 Seed-forms of organic substance — simple carbon 

 compounds — may have first appeared, and these 

 would serve as the basis of gradually increasing 

 complexity of molecules through a possibly long- 

 continued process of deoxidation and formation of 

 higher carbon and nitrogen compounds, until true 

 organic matter appeared and the chemistry of life 

 had begun, 



Baldness Microee. — One of the physicians at a 

 hospital in Paris has, it is stated, discovered a 

 microbe of the skin which accounts for baldness. 

 A sheep and a rabbit has been inoculated with the 

 microbe at the Pasteur Institution, and the results 

 will be made known at an early meeting of the 

 Society of Dermatology. 



Queries. — May we remind our readers that we 

 shall be glad at all times to afford what assistance 

 we can by inserting in these columns their queries 

 on microscopic matter and methods. 



Answers. — R. Borrows : Your determination is 

 correct. /. T. ■ Please repeat your query. T. 

 Clarke : The specimen sent is a sheep-tick (Malo- 

 phagus ovinus.) 



