Journal of Applied Microscopy. 



39 



should not be placed In water, since the 

 walls of the epidermics are mucila- 

 ginous. The seeds of Berberidaceae can 

 also be mounted and prepared like those 

 of Leguminosae. It should be noted 

 here, that the endosperm in both cases 

 will soon become so pale that its struc- 

 ture can only be made out with diffi- 

 culty. One section should therefore be 

 stained either with haematoxylin or the 

 analine dyes and mounted with the 

 unstained preparations. 



Pig. 6.— Vigna catjang, Walp. (cow pea.) 

 cross section of cotyledon. 



s.— Starch grains, different sizes. 



Large grains show numerous rifts, 

 a.— Amyloplast. 



d.— Aleurone grain, crystalloid and glob- 

 oid, 

 b.— Cell wall. 



p.c. — ^Wall with pore canals, 

 i.— Intercellular space, 

 d. — Cytoplasmic membrane, 

 n.— Nucleus and nucleolus. 



X 220. (Original.) 



Phlorglucin, so well known in labora- 

 tory work, should always be applied to 

 testa, for in different orders variation 

 occurs with reference to lignification. In 

 Cucurbitaceae, the malpig'hian cells are 

 lignifled in Rhamnaceae only in some 

 genera. They are not lignifled in most 

 of the Leguminosae nor in Marslliaceae. 

 When lignin is not present the cell-wall 

 consists of cellulose; phlorglucin and 

 hydrochloric acid often gives the cell- 

 wall a bluish tinge. It is not difficult 

 to separate the seeds of some orders by 

 their micro-chemical behaviors and 

 microscopic characters. 



In making these studies it is essential 

 to cut fresh sections for each test. 



L. H. Pammel. 



Iowa State College of Agriculture and 

 Mechanic Arts. 



If Dleased with the Journal give us 

 your support — financially. 



Notes on Microscopical Tech- 

 nique. 



G. Carl Hubee, M. D. 



I have been asked by the editor of the 

 Journal to prepare a series of short 

 articles on microscopical technique, giv- 

 ing methods for hardening tissues, of 

 imbedding them in paraffin and celloidin 

 preparatory to cutting sections, for sec- 

 tion cutting, for staining sections, and 

 for making and staining blood prepara- 

 tions. I am further instructed to pre- 

 sent these methods in such simple form 

 that persons unacquainted with the most 

 modern aspects of microscopical tech- 

 nique may be able to understand and 

 use them without difficulty. The micro- 

 scope has in the last few years become 

 so essential an adjunct to the physi- 

 cian's equipment, such help in making 

 a diagnosis in many of the cases met 

 by him, that he above all realizes fully 

 the necessity of knowing how to use 

 this instrument properly. There are, 

 however, many physicians who have not 

 had time nor opportunity to acquaint 

 themselves with the methods known to 

 the investigators in the laboratories, 

 who nevertheless feel a want in this 

 direction. To meet this want, at least 

 partially, this series of articles is 

 prepared, and in selecting the methods 

 to be given, I have endeavored to choose 

 such as are easy of manipulation, not 

 expensive and not very time-consuming. 



THE HARDENING OF TISSUES FOR MICRO- 

 SCOPICAL EXAMINATION. 



It is hardly necessary to say that it is 

 quite impossible to cut even moderately 

 thin sections of the great majority of 

 the tissues removed at an operation or 

 at a post-mortem examination. An 

 attempt to do so will soon convince one 

 of the difficulties attending such a pro- 

 cedure. To facilitate the cutting of thin 

 sections, to preserve as nearly as possible 

 the relative positions of the various ele- 

 ments of the tissues thus sectioned, and 

 to retain as accurately as can be the 

 structure of these elements, various 

 hardening or fixing fluids have been sug- 

 gested. The number of such hardening 

 or flxing fluids is now very great; some 

 have a very wide application, others are 

 useful in certain special examinations, 

 others again have a very restricted field 

 of usefulness. They all harden the tissue 

 and all preserve more or less faithfully 

 the tissue elements in the condition in 

 which they were when placed in the 

 hardening fiuid. Of this nuniber I shall 

 mention only three, the three which 

 seemed to me would prove most gener- 

 ally useful in the kind of microscopical 

 work a physician may be called upon 



