ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



999 



trivance for the lodging of ants, in the form of bladders on the leaf-stalk 

 or upper surface of the leaf. 



The author concludes with a classification of the various contrivances 

 for tbe accommodation of ants, which he divides in the first place into 

 axial cavities, and chambers connected with the leaves. 



Comparative Cultures of the same species at different altitudes.* — 

 M. Gr. Bonnier has undertaken the culture of a certain number of species 

 at different altitudes in the Alps and Pyrenees. In all cases certain 

 plants were sown, while others were planted. When a sowing was to be 

 made, the packet of seeds was divided into three lots, one was sown at 

 a high altitude, another at a medium altitude, and the third at Paris. 

 Tbe author found that the plants he experimented with were very 

 imequally affected bv this change in their external physical conditions. 

 Thus Thymus Serpyllum, for instance, changed much less in aspect than 

 Lotus corniculatus or Leontodon autumnalis. It may be laid down as a 

 general rule that annuals or biennials are much less modified than 

 perennials. The author then compares Teucrium Scorodonia grown at 

 high altitudes in the Pyrenees with that grown in Paris. In the former 

 case the plants produced very short aerial stems, with deep green hairy 

 leaves, while in the latter case the stems were much longer, the green 

 of the leaf much lighter, and hairs less numerous. 



B. CEYPTOGAMIA. 



Cryptogamia Vascularia. 



Antherozoids of Cheilanthes hirta.f — M. Leclerc du Sablon has 

 carefully followed out the mode of formation of the antherozoids in this 

 fern. In the way in which the mother-cells of the antherozoids are 

 formed, there is no essential difference from that described by Stras- 

 burger in the case of Polystichum aculeafum. When the antherozoid is 

 about to be formed, the nucleus of the mother-cell becomes first eccentric ; 

 then a portion of the protoplasm forms a hyaline ring round the cell in 

 contact with the nucleus ; the nucleus then elongates itself to the length 

 of this ring, and forms the body of the antherozoid ; the greater part of 

 the hyaline ring is employed in the formation of the cilia ; the rest forms 

 the thin protoplasmic envelope of the antherozoid. This vesicle plays no 

 essential part in the process of impregnation. 



Apogamy in Notochlgena.|— Prof. S. Berggren records an additional 

 instance of apogamy among ferns, in the case of Notoclilsena distans from 

 New Zealand, which differs in some respects from the well-kno?vn example 

 of Pteris cretica. From the anterior incision in the prothallium there 

 proceeds a ligulate lobe, usually unilamellar, but sometimes composed of 

 several layers of cells. This may again produce a similar lobe at its 

 apex. As the central lobe possesses a fibrovascular bundle, it may be 

 regarded as an intermediate structure between an ordinary prothallium 

 and the first leaf of a young fern. Near the apex of the central lobe a 

 papilla-like swelling is formed by cell-division, which developes into the 

 rudiment of the first leaf of the young shoot. Between it and the margin 

 of the central lobe is the apex of the young stem ; the second leaf is 

 formed at the opposite side of the apex, and at a later period the first root. 



* Bull, Soc. Bot. France, xxxiv. (1888) pp. 467-9. f Ibid., xxxv. pp. 238-42 

 % Bot. Notiser, 1888, pp. 14-6 (1 tig.). See Bot. Central bl., xxxv. (1888) p. 183." 



