ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 1025 



of several cells, and the opening is directed downwards. The base 

 of the pitcher always contains fewer animal remains than Sarracenia. 



Vegetative Organs of Monotropa.* — M. F. Kamienski describes 

 in detail the structure of Monotropa hypopitys. The most important 

 point of his observations refers to the root, which he finds to be 

 covered externally by the mycelium of a fungus, which branches 

 abundantly and forms a pseudo-parenchymatous envelope, often two 

 or three times the thickness of the epidermis itself, being especially 

 well developed at the apex of the root. It is entirely superficial, not 

 penetrating into the living cells, though occasionally between the 

 epidermal cells. The species of this fungus M. Kamienski was unable 

 to determine, but considers it to be probably identical with that found 

 on the roots of conifers and other trees. f 



With regard to the mode of nutrition of Monotropa, M. Kamienski 

 decides that it is not a parasite ; the most careful examination failed 

 in detecting any haustoria or other parasitic union with the root of any 

 " host." He regards it as deriving its nutriment from the soil through 

 the medium of the fungus-mycelium by which the roots are invested ; 

 the only parts of the root which are in actual contact with the soil 

 are composed of lifeless cells with no power of deriving nutriment 

 from it. The connection of the fungus with the roots of the Monotropa 

 is not one of parasitism, but of true symbiosis, each of the two 

 organisms deriving support and nutriment from the other. 



Protection of Leaves from excessive Transpiration. | — Herr E. 

 Fleischer describes the various modes in which plants are protected 

 against too great a loss of water through their leaves in respect of 

 (1) the size, form, and position of the leaves ; (2) the number, size, 

 and structure of the stomata ; (3) the size and form of the intercel- 

 lular spaces; (4) the thickness of the outer epidermal walls, including 

 formation of cuticle, coating of wax, or covering of hairs ; (5) nature 

 of the cell-contents ; and (6) vital functions of the protoplasm. 

 Those plants which are best protected against desiccation have a 

 feeble energy of growth from the small quantity of carbonic acid 

 which they absorb, and also from their small absorption of water in 

 consequence of the diminished transpiration. Such plants are unable 

 to maintain themselves in moist situations, and confine themselves to 

 dry localities, while their leaves usually persist through two periods 

 of vegetation ; in the temperate zone they are mostly evergreen trees 

 and shrubs. 



Heterophylly of Eucalyptus globulus.§ — Sig. G. Briozi suggests 

 the following history of the dimorphism of the leaves of this tree. 

 He supposes the original form and position of the leaves to have been 

 broad and horizontal, and that the tree is probably descended from 

 ancestors adapted to totally dififerent climatic conditions. The vertical 



* Mem. Soc. Nation. Sci. Nat. Cherbourg, xxiv. (1884) pp. 5-40 (3 pis.). 



+ Soe this Journal, ante, p. 844. 



J Fleischer, E., ' Die Schutzeinrichtungen der Pflanzenblilttor gegen Vcr- 

 trocknung ' (1 pi.), Dobein, 188.5. See Bot. Centralbl., xxii. (18S5) p. HSG. 



§ Mem. Acca'l. Lincei, xiv. (1883) pp. 136-42. See Naturforscher, xviii. 

 (1885) p. 296. 



