SCIENCE-GOSSIP. 



149 



raicroscopist, very interesting pest, the flea. Fleas 

 lay their ejgs in cracks, in cushions and in boards, 

 or in the midst of dust ; and their larvae, which 

 have no legs and which therefore must live where 

 they have been born, can only exist in consequence 

 f the nourishment brought to them by adults. 

 Were they abandoned they would perish, but they 

 have excellent mothers who never leave them ; 

 for after a flea, should it be a mother, has gorged 

 ith blood, it seeks its young and disgorges 

 a small quantity so as to keep them alive. The 

 larvae shut themselves up in silken cocoons when 

 they have attained their full size, and undergo 

 their metamorphosis into the condition of nymphs. 



Mosquitoes. — Our readers will, probably, have 

 noticed the great prevalence of mosquitoes this 

 summer, but familiar though they may be with the 

 methods of its attack, few have any idea of the 

 complicated apparatus with which this fly works 

 ::s mischief. The beak of the mosquito is simply 

 a tool-box wherein the mosquito keeps six 

 miniature surgical instruments in perfect working 

 order. Two of these instruments are exact 

 rrparts of the surgeon's lance, one is a spear 

 with a double-barbed head, the fourth is a needle 

 of exquisite fineness, a 

 saw and a pump going 

 to make up the comple- 

 ment. The spear is the 

 largest of the six tools, 

 and is used for making 

 the initial puncture ; 

 next the lances or knives 

 are brought into play 

 to cause the blood to 

 flow more freely. In 

 case this last operation 

 fails of having the de- 

 sired effect, the saw and 

 the needle are carefully 

 and feelingly inserted in 

 a lateral direction in 

 the victim's flesh. The 

 pump, the most delicate 

 of all six of the instru- 

 ments is used in trans- 

 ng the blood to the 

 insect's stomach. 



The Hen Flea — This parasite has a wide 

 zcographical distribution, a fact that is due to its 

 •n one locality to another by birds. 

 "ackard illustrates in "Insect Life" 

 pecimens thai were obtained from an owl 

 1. representing the male, with the antennae 

 1 pi enlarged. Dr. Julius Wagner, of the 

 Laboratory, Imperial University of 

 ng much attention to the 

 -aptera, and is desirous of obtaining speci- 

 mens from here or abroad. 



Re; - Lamms 1 iiatoms, —In the 



the Royal Society of Edinburgh," 

 Mr ', Mjt- -j.irkable observa- 



tion* on th* of certain pelagic 



diatoms colI< Scotland, 



■ ' ysts " 

 ' cell, with only 



lo have 



i m'jltit" 

 atenfr.. form \ 



coiicinnus, but in this species the protoplasm 

 divides before the production of the " cysts," two 

 of which were found within the same parent 

 frustule, differing from one another in form and in 

 the width of the girdle-zone. It is not uncommon 

 to find the young colonies of Coscinociiscus in 

 " packets " of eight or sixteen, this being apparently 

 the result of further binary division within the 

 frustules, which are found accompanying them in 

 an empty state. The membranes of these young 

 colonies are only very slightly silicified, or not at 

 all ; and they are, therefore, capable of increasing 

 in size. A similar formation of "packets" of 

 eight or sixteen young individuals within the 

 parent frustules was observed in several species of 

 Cliaetoceros. 



Preservation of Algae. — The following method 

 for the preservation of the colours of freshwater 

 algae and desmids will be found to be most effective. 

 Place the algae in a watch-glass in camphor-water 

 to which a few drops of glycerine have been added. 

 At first it will become a yellow colour, but after a 

 few hours the original green returns in its full 

 vividness. It should then be mounted in a cell 



with a portion of the 



F:.ea from Owl. 



Sarcoptylla galliuacea : male, enlarged ; 

 palpi, more enlarged. 



a. antennae; b, 



', avings by Packard.) 



fluid. A specimen of 

 Draparnaldia " plumosa 

 mounted twenty years 

 ago in this way is to- 

 day as beautifully green 

 as at first, and the 

 chlorophyl seems to be 

 unchanged. 



Manchester Micro- 

 scopical Society. — At 

 the Annual Soiree of 

 the Manchester Micro- 

 scopical Society, which 

 is to be held in the 

 Athenaeum on October 

 2nd, Mr. F. \V. Keeble, 

 of Owens College, Man- 

 chester, will deliver a 

 lecture entitled "Im- 

 pressions of Tropical 

 Life." 



Bacterium Living 

 in Alcohol. — From 

 "Natural Science" we learn that Mr. and Mrs. 

 Victor H. Veley, of Oxford, have recently dis- 

 covered a micro-organism in some faulty rum that 

 had been sent to them for examination. For some 

 time past the colony of Demerara has suffered 

 considerable monetary loss owing to the un- 

 accountable manner in which the rum that it 

 exported depreciated in quality. The depreciation 

 has now been traced to the presence of a bacterium 

 which belongs to the group Coccaceae. The fact of 

 any micro-organism existing and multiplying in 

 spirit correctly assessed at 42 over proof, or about 

 74 per cent, by weight, is of great interest both 

 from a scientific and technical point of view. 



to Correspondents. — Major-General 

 !•;. Warrand, of Westhorpe Hall, Southwell, desires 

 , ! lot atities for collecting mil 

 material in the vicinity of Southwell oi 



bettei 1 olla ting grounds 



In the kingdom than the pools, drains and hi 



I |m oln torn bo 

 1 1 11 1 can give no Information, bul 

 ill kindly a Isl 

 era! Wan 



