ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 123 



The fixing of the coloured spores with lac on white paper answers 

 completely ; but, in the case of the Leucospori, only those of species 

 of Bussula and Lactarius unite firmly with the resin of the lac. On 

 the other hand, the mode of fixing the white spores on blue cardboard 

 simply with gelatine appears to answer in all cases ; but the solution 

 should be somewhat more dilute than previously stated. The best 

 fluid is a warm solution of 1 part gelatine in a mixture of 150 parts 

 water and 150 parts alcohol. This answers with species of Bussula 

 and Lactarius, while with Agaricus (Collyhia) radicatus &o concentrated 

 a solution as 1 part gelatine in 30 parts water is necessary. The 

 writer gives a list of a number of species, with the strength of solution 

 required in each case. Some spores can be fixed on blue cardboard 

 by the use of pure water only. In some cases, again, it is necessary 

 to heat the solution strongly. Agaricus [Collyhia) maculatus, A.(C.) 

 velutipes, and Marasimus peronatus require a different treatment, which 

 is described. 



The author found the same results with the fluid recommended by 

 Patouillard (2 parts mastic in 15 parts ether) as with the lac ; the 

 resin does not in all cases combine well with the white spores. 

 The ether has some advantages in penetrating the paper more rapidly 

 and completely, but, on the whole, Herpell prefers the use of 

 alcohol. 



Dissociation of Gland-Elements.* — Cauderau finds boiling the 

 mucous membrane of the stomach in a solution of nitrate of soda a 

 very good process for isolating the glands and gland-elements, but the 

 constituent parts of the tissues become too brittle. This defect can be 

 obviated by a previous immersion of some minutes in osmic acid. 

 The cells will then remain admirably preserved after boiling for three 

 hours, but can scarcely be stained at all. The following combination 

 is therefore recommended : — One part of Miiller's fluid is diluted with 

 two parts of water and about 30 to 40 grammes of the sodic nitrate is 

 dissolved in a litre of the mixture. Boiling for three hours in this 

 compound is sufficient to break up the mucous membrane of the 

 stomach. The maceration, besides acting on the glands, extends to 

 the muscular coat. 



Method of Preparing^ and Mounting Soft Tissues.! — The con- 

 clusions arrived at with regard to the structure of the nervous centres 

 by means of the successive action of bichromate of potash and nitrate 

 of silver will certainly receive confirmation from this method, which 

 we owe to Professor C. Golgi, It has the double advantage of 

 enabling us to stain the nerve-cells black within a given time, and of 

 turning out preparations which may be kept for a long period in the 

 ordinary mounting media. 



The pieces of tissue are hardened to the necessary degree in 

 Miiller's fluid, or in solutions of bichromate of potash, whose strength 



* Gaz. m6d. de Paris, No. 45, pp. 577-8. Cf. Jahresber. Anat. u. Physiol., 

 viii. pp. 13-14. 



t Rendiconti R. Istit. Lombard., xii. pp. 206-10. Cf. Jahresber. Anat. u. 

 Physiol., viii. pp. 12-13. 



