330 Physiologie. — Palaeontologie. — Algae. 



replacement b}*- a branch, which at first grows at a right angle to 

 the axis from which it Springs, is a selected phenomenon, by which 

 the plant, the shoot of which is under unfavorable conditions, tests 

 a wholly different line, instead of using itself up in one attempt to 

 reach a place where conditions are good. Jongmans. 



Hooker, H. D., Physiological observations on Drosera 

 rotundifolia. (Bull. Torrey Botan. Club. XLIII. p. 1—27. 11 text flg. 

 1916.) 



The red pigment which is found in the leaves and roots of 

 Drosera rotundifolia is probably trihydroxylmethylnaphtoquinone. 



The rosette habit is conditioned by transpiration. 



The inflexion of Drosera tentacles is produced by an accelera- 

 tion of the rate of growth on the convex side and in the median 

 section. The unbending is caused by an increase in the rate of 

 growth on the concave side and in the median section, accompanied 

 by compression of the convex side. 



In both cases the acceleration commences near the base and 

 extends towards the gland. The amount of growth is greatest near 

 the base and decreases apically. 



A tentacle is capable of reacting three times. During each 

 reaction an apical portion of the bending region becomes fully 

 grown. Drosera tentacles have intercalary, basipetal growth. 



The bending of the exterior tentacles is nastic; of the central 

 tentacles, tropic. The unbending is in all cases owing to autotropism. 



Jongmans. 



Forsaith, C. C, A report on some allochthonous peat de- 

 posits of Florida. Part I. Topographical. (Botan. Gazette. 

 LXII. p. 32-52. 1 Diagram. 1916.) 



This part contains the description of the different deposits 

 examined by the writer. The object of the investigation is to deter- 

 mine the relative amounts of the two main types of peat formation. 

 The allochthonous deposits are those which are represented by a 

 gradual amassing of drifted, wind-blown, and sedimentary vege- 

 table material in permanent, open, and quiet bodies of water. The 

 autochthonous are those which have resulted from a gradual accu- 

 mulation of successive generations of plants in situ, in the presence 

 of more or less permanent but concealed water. 



Allochthonous peat is characteristic ofdeep permanent lakes and 

 the lower portion of marshes; autochthonous peat is characteristic 

 of the Upper portions of marshes, the upper strata of filled lakes, 

 and swamps. 



From what studies it was possible to make in regard to the 

 average extent of these two types of peat formation it is evident 

 that those of a lacustrine. character (allochthonous) are of vastly 

 greater numerical and quantitative importance than those of an 

 autochthonous nature. Jongmans. 



Roe, M. L., A contribution to ourknowledge of Splachni- 

 dium. (Botan. Gazette. LXII. p. 400—408. PI. 14-18. 1916.) 



Splachnidium rugosutn Grev. is a monotypic genus, which has 

 been placed by various investigators in different groups. Most 



