ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 587 



the aceto-carmin preparations of the whole gonad are very useful for 

 mapping out quickly the main facts of spermatogenesis, they are not 

 permanent, not so good for finer details, and not useful for somatic 

 mitosis. 



New Reaction of Fats.* — L. Martinotti states that a group of dyes 

 belonging to the class of amino-azo compounds has the property of 

 fixing fats, and in the presence of an oxidizing agent of making them 

 insoluble. In staining by this method, in which chrysoidin and 

 chromium are the essentials, the material is fixed in 10 p.c. formalin, 

 and the sections, cut on a freezing microtome, are immersed for five to 

 ten minutes or so in a 1 p.c. aqueous solution of chrysoidin. After a 

 wash, the sections are immersed in 10 p.c. chromic acid or potassium 

 bichromate for one minute, then washed and mounted. 



(5) Mounting 1 , including- Slides, Preservative Fluids, etc. 



Mounting Microfungi.f — J. Burton recommends the use of the 

 following medium as an excellent staining - mounting fluid : Pure 

 glycerin 3 parts, distilled water 1 part, Hoffman's blue solution q.s. 

 The exact quantity of the blue solution cannot be stated, but sufficient 

 should be added to tint the fluid a rather dark blue when in bulk. 



(6) Miscellaneous. 



Diascopy of Traces of Blood.J — Angelo de Dominicis finds that the 

 following procedure serves to detect traces of blood in cases where all 

 other methods fail, and is especially valuable where a very small quan- 

 tity of blood is present on heavily rusted iron. With dried blood 

 adhering to a substrate, a scarcely visible particle is introduced into a 

 trace of origanum oil on a Microscope slide placed on a white back- 

 ground, and is thoroughly disintegrated by means of the rounded end 

 of a glass rod. After the addition of a drop of a saturated or more 

 dilute solution of eosin in paracetaldehyde, the preparation is examined 

 in artificial light passing through a suitable diaphragm. A drop of 

 euparal may be employed subsequently to render the preparation per- 

 manent. Where the blood has penetrated the subtrate, the latter mid 

 the blood are scraped off by means of a sharp knife in the form of a 

 fine powder, which is treated as above. Particles of blood appear 

 wholly or partly coloured, and the red corpuscles, in groups or isolated, 

 may be distinguished ; the diameter of the corpuscles can be measured. 



. Study of Restitution Masses. § — W. De Morgan and G. H. Drew 

 in their study of the restitution masses formed by the dissociated cells 

 of the Hydroids, Antennularia ramosa and A. antennina, followed the 



* Zeitschr. Phys. Chern., xci. (1914) pp. 425-39. 

 t Journ. Micrology (1914) p. 71. 



X Boll. Chim. Farm., liii. (1914) pp. 162-3. See also Journ. Chem. Soc, cv. 

 and cvi. (1914) ii. p. 759. 



§ Journ. Marine Biol. Assoc, x. (1914) pp. 440-63 (9 figs.) 



