436 



THE MICROSCOPE. 



through a slit in a piece of cork, use it as a forceps under 

 a two-thirds of an inch objective, with an erecting eye- 

 piece. When the split extremity of the hair touches the 

 glass-slide, its parts separate from each other to an amount 

 proportionate to the pressure, and on beiLg brought up to 

 the object, are easily made to seize it, when it can be 

 transferred as a single specimen to another slide without 

 injury. The object is most easily seized when pushed to 

 the edge of the fluid on the slide. Hairs split at the ex- 

 tremity may always be found in a shaving-brush which has 

 been in use for some time. Tho£e should be selected which 

 have thin split portions so closely in contact that they 

 appear single until touched at their ends. I have also 

 found entire hairs very useful, when set in needle-holders, 

 in a similar manner ; any amount of flexibility being given 

 to them by regulating the length of the part of the hair 

 in use." Professor Smith, of Kenyon, U.S. contrived a 

 very ingenious "Mechanical finger " for picking up and 

 arranging diatoms and other minute objects. 



Professor J. W. Bailey, of New York, has enriched the 

 Museum of the College of Surgeons with several valuable 

 specimens of the skeletons of Infusoria; among them is a 

 fresh-water Bacillaria, named Meridian circulare, which 

 Professor Quekett, in the Historical Catalogue, describes 

 as " consisting of a series of wedge-shaped bivalve siliceous 

 loricse, arranged in spiral coils ; when perfect, and in cer- 

 tain positions, they resemble circles ; each lorica is articu- 

 lated by two lateral surfaces." It is asserted that they 

 creep about when free from the stalk-plate. (Fig. 225, No. 

 16.) Gocconema lanceolata have two lanceolate flinty cases 

 that taper towards their ends, one of which is attached to 

 a little foot. Each lorica has a line marked in its centre, 

 and transverse rows of dots on both sides : Ehrenberg says 

 there are twenty-six rows in the one-hundredth of a line. 

 (Fig 225, No. 14.) Achnanthes Longipes have at the 

 margins two coarse convex pieces roughly dotted, and two 

 inner pieces firmly grooved ; the inside seems filled with 

 green matter. At one corner they are affixed to a jointed 

 pedicle, which in many specimens contains green granules. 

 In a specimen of a fossil Eimotia, found in some Bermuda 

 earth, the flinty case is ii four parts; it is of a half- 



