So 



MOUNTING AND LABELING. 



Some workers prefer a book catalog. Very excellent book catalogs have 

 been devised by Ailing and by Ward (Jonr. Roy. Micr. Soc, 1S87, pp. 173, 348; 

 Amer. Monthly Micr. Jour., 1890, p. 91 ; Amer. Micr. Soc. Proc, 1887, p. 233). 



The fourth section in the cataloging formula has been introduced, as there is 

 coming to be a belief that the tissues of young and of old animals differ in respect 

 to the size of the nuclei (see Minot in Proc. Amer. Assoc. Adv. of Science, 1890, pp. 

 271-2S9). It is also extremely desirable to know whether the animal is well or 

 ill nourished, healthy or diseased. 



CABINET FOR MICROSCOPICAL PREPARATIONS. 



\ 183. While it is desirable that microscopical preparations should be properly 

 labeled and cataloged, it is equally important that they should be protected from 

 injury. During the last few years several forms of cabinets or slide holders have 

 been devised. Some are very cheap and convenient where one has but a few 

 slides. For a laboratory or for a private collection where the slides are numerous 

 the following characters seem to the writer essential : 



(1). The cabinet should allow the slides to lie flat, and exclude dust and light. 

 (2). Each slide or pair of slides should be in a separate compartment. At each 

 end of the compartment should be a groove or bevel, so that upon depressing 

 either end of the slide the other may be easily grasped (Fig. 40). It is also desir- 

 able to have the floor of the compartment grooved so that the slide rests only on 

 two edges, thus preventing soiling the slide opposite the object. 



(3). Each compartment or each space sufficient to contain one slide of the 

 standard size should be numbered, preferably at each end. If the compartments 

 are made of sufficient width to receive two slides, then the double slides so fre- 

 quently used in mounting serial 

 sections may be put into the cab- 

 inet in any place desired. 



(4). The drawers of the cabi- 

 net should be entirely indepen- 

 dent, so that any drawer may be 

 partly or wholly removed with- 

 out disturbing any of the others. 

 (5). On the front of each draw- 

 er should be the number of the 

 drawer in Roman numerals, and 

 the number of the first and last 

 compartment in the drawer in 

 Arabic numerals (Fig. 39). 

 Fig. 39. — Cabinet for Micro- 

 I scopical Specimens, showing the 

 method of arrangement and of 

 numbering the drawers and in- 

 dicating the number of the first 

 and last compartment in each 

 drawer. It is better to have the 

 slides on which the drawers rest 

 Fig. 39. somewhat shorter, then the 



rJriwe r -front mm- b Q futile qrid n^t notched ae here shown. 



