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21 



according to Nature, details the results of investigations on the pres- 

 ence of chlorophyll in the epidermis of leaves. Hitherto it has gen- 

 erally been supposed that submerged phaenogamous plants, with a 

 i^^ exceptions, contain chlorophyll in their epidermis, while terres- 

 trial phaenogams, also with a few exceptions, have an epidermis des- 

 titute of chlorophyll. Herr Stohr's experiments, .however, point to 

 a different conclusion. He finds that while chlorophyll is contained 

 in the epidermis of most of the broad-leaved gymnosperms and of by 

 far the greater number of terrestrial phaenogams, it is absent from 

 that of the needle-leaved gymnosperms and the terrestrial monocoty- 

 ledons. In most cases the chlorophyll does not occur in the epider- 

 mis of the upper surface of the leaf, being quickly destroyed on its 

 formation by a too intense light; but is only to be found in that of 

 the under surface and also of the leaf petioles and stipules. So far 

 as the evolution of the chlorophyll bodies was observed the latter 

 showed themselves as starch-chlorophyll bodies. These experiments 

 were made upon the leaves of nearly one hundred species. 



Changes in the Diameter of the Trunks of Trees. — According to 

 the Gardeners' Chronicle, MM. Kraus and Kaiser have been makine 



some researches from which it appears that the trunks of trees under- 

 go daily changes in diameter. From early morning to early after- 

 noon there is a regular diminution till the minimum is reached, when 

 the process is reversed and the maximum diameter attained at the 

 time of twilight; then again comes a diminution, to be succeeded by 

 an increase about^ dawn — an increase more marked than that in the 

 evening. The variations in diameter coincide, therefore, with those 

 of the tension, but they are shown to be inverse to the temperature, 

 the maximum of the one corresponding roughly ,to the minimum of 

 the other, and so on. 



Preparation of Toadstools for the Herbarium, — In a receiitly-re- 

 ceived check-list of plants sent us by the Schlesischen Botanischen 

 Taiisch- Vereins^ we find a method, as practised by Herr E. Jacobasch, 

 of Berlin, of preparing fleshy species of fungi for the herbarium, and 

 which, briefly stated, is as follows: The 'perfectly fresh toadstool is 

 divided vertically through the centre and the two halves are laid down 

 on stout paper with liquid glue and then submitted to a gentle pressure. 

 The glue immediately penetrates the substance of the fungus and ex- 

 pels all the water contained therein, and so quickly too that in a few 

 minutes the whole surface of the pileus will be seen covered with bead- 

 like drops of moisture. The glue, moreover, drives out or destroys all 

 the insect larvae that may be present. The preparation after one or 

 two days will be found thoroughly dry, and its color, with the ex- 

 ception of being a little darker, will be perfectly preserved. The 

 spores having been collected on paper in the usual manner, are af- 

 fixed thereto by immersion in milk. Further notes on this same 

 subject will be found on another page. 



i8. Botanical Literature. — Tnmen's /our nai of Botany for Jslu- 

 uary contains articles on ' Chara obtusa, a species new to Britain,' by 

 H. and J. Groves; 'History of the Scorpoid Cyme,' by Sidney H. Vines; 

 ^ Potamogeton lanceolatus of Smith,' by C. C. Babbington;* Musci 



