784 SUMMARY OF CURBENT RESEARCHES RELATING TO 



been precipitated be redissolved in a saccharated solution passed through 

 a Chamberland filter and fermented. Hence the action of the yeast 

 upon the soluble casein, the casein in suspension, and the precipitated 

 and redissolved casein, is the same, 



7- General. 



Development of Annual Plants.* — In a further paper on this sub- 

 ject M. H. Jumelle states that when plants are grown in a medium 

 deprived of salts, the absence of the salts not only causes a natural 

 diminution of dry substance which is directly due to this absence, but 

 the proportion of water in relation to the dry weight of the plant is also 

 diminished. This results in certain anatomical and morphological modi- 

 fications, which always accompany the diminution of the quantity of 

 water in a plant. The large proportion of water in plants rich in salts 

 is due to the slowness of the transpiration, and especially to the augmen- 

 tation of the absorption. When a plant is provided with salts, but is 

 grown in complete darkness, the absorption of mineral substances is 

 excessively feeble, and takes place especially at the commencement of 

 vegetation. The large proportion of water present which characterizes 

 a plant grown in darkness is here also due to the slowness of the tran- 

 spiration, and especially to the increase in the absorption. 



Esparto-grass. j — Mr. J. Christie gives a careful description and 

 drawing of the appearance presented under the Microscope of a trans- 

 verse section of the leaf of the esparto-grass, Macrochloa tenacissima. On 

 the upper surface of the leaf are a number of deep grooves or furrows, 

 characteristic of grasses growing in very dry localities. These are 

 clothed with unicellular hairs. Bands of fusiform cells, with strongly 

 thickened and lignified walls, stretch from the upper to the lower epiderm, 

 giving strength and rigidity to the leaf. 



B. CRYPTOGAMIA, 



Prof, de Bary's Microscopical Slides. — The collection of micro- 

 scopical slides made by the late Prof, de Bary in the course of his work 

 has been purchased by the Trustees of the British Museum. A few 

 duplicate slides in use for teaching purposes had been acquired by the 

 Botanical Institute in Strassburg University, and the slides of Bacteria 

 have been kept by Dr. A. de Bary, of Frankfurt, in whose hands, as a 

 skilful experimenter in this department of work, they will no doubt 

 prove fruitful of results. The collection is therefore complete except 

 the Bacteria, and the following statement of its contents may be of 

 interest: — The slides of Fungi are 1220 in number, consisting of 

 283 Peronosporese, 59 Saprolegnie^, 76 Mucorini, 54 EntomoiDhthore^, 

 321 Ascomycetes, 217 Uredinea^, 10 Chytridiese, 67 Ustilaginese, 

 73 Hymenomycetes, and 60 Gastromycetes. Of other Cryptogams and 

 Vascular Plants there are 1808 slides, representing Lichens, Characese, 

 Alga3, Mosses, and Vascular Plants, making in all 3028 belonging to 

 what may be called for Museum purposes the systematic series, tbouuh 

 of course everybody knows the importance of these slides to the student 

 of morphology. In addition there are 1112 slides illustrating anatomical 



* Kev. Gen. de Bot. (Bonnier), i. (1889) pp. 359-89, 43U-7 (2 pis. and 1 fig.). 

 Of. this Journal, ante, p. G68. t Paper-trade Eev., xii. (1889) 2 pp. and 1 pi. 



