360 MORPHOLOGY, ETC., VASC. PLANTS [Bot. Absts. 



it is likely to be a type evolved from them and the two genera might be included in the same 

 genus; although the author believes that Robert Brown's separation of them is correct. — John 

 W. Harshberger. 



2445. Sotjeges, R. Les premieres divisions de l'oeuf et les differenciations du suspenseur 

 chez le Capsella Bursa-pastoris Moench. [The first divisions of the egg and the differentiations 

 of the suspensor in Capsella Bursa-pastoris Moench.] Ann. Sci. Nat. Bot. X, 1: 1-28. 1919. 

 ■ — The first division of the egg was found to give an apical and a basal cell, separated by wall 

 at right angles to length of pro-embryo (horizontal) ; next mitoses led to horizontal wall across 

 basal cell and vertical wall in apical cell, producing 4-celled stage of pro-embryo. Author 

 points out that subsequent history of 2 lower cells of this stage has not been well known, and 

 he made a cell lineage study on these two lower cells. The lower one of the 2 gave rise to a 

 vesicular basal cell and 2 cells of filamentous part of suspensor; the second (intermediate 

 cell of four-celled pro-embryo), by a horizontal division wall gave 2 cells, and later by simi- 

 larly redividing made progeny of intermediate cell 4; a total of 6 cells made up filamentous 

 part of suspensor at this stage. Last phase in development of suspensor is that which leads 

 to hypophysis: of 6 cells just mentioned, 4 basal ones made part of adult suspensor and di- 

 vided no further; terminal 2 divided transversely once, making a total of 8 for filamentous 

 portion of complete suspensor; the terminal cell became hypophysis. Typically, then, of 

 cells present at 4-celled stage, intermediate (second from base) gave rise to 6 distal cells of 

 suspensor; and basal cell of 4 led to 2 cells of suspensor and vesicular cell at base of pro-em- 

 bryo. Some exceptional pro-embryos discussed. One seemed due to an additional direct 

 (amitotic) division in vesicular cell. — James P. Kelly. 



2446. Steckbeck, D. Walter. The comparative histology and irritability of sensitive 

 plants. ContrhVTJniv. Pennsylvania Bot. Lab. 4: 185-230. PI. 58-65. 1919. 



2447. Steil, W. N. Secondary prothallia of Nephrodium hirtipes HK. Trans. Amer. 

 Microsc. Soc. 38: 229-234. PI. 25-26. 1919. — Culture medium used was sphagnum saturated 

 with Knop's solution placed in small Stender dishes and thoroughly sterilized. Healthy 

 prothallia were placed on this medium and exposed to subdued light for two weeks. Short 

 filaments one cell thick were produced from the margins and both surfaces of the prothallia. 

 The cultures were then placed in a Wardian case under favorable light conditions. The fila- 

 ments broadened out and became heart shaped, and when cut off became independent pro- 

 thallia and produced embryos apogamously. Several other species of ferns under the same 

 treatment produced prothallia; but onlyTin the case of Nephrodium were embryos produced 

 apogamously.— S. H. Essary. 



2448. Styger, Jos. Beitrage zur Anatomie der Umbelliferenfruchte. [Contributions on 

 the anatomy of umbelliferous fruits.] Schweiz. Apoth. Zeitg. 57: 125-126. 143-145. Fig. 10- 

 12. 1919— See Bot. Absts. 3, Entry 1697. 



2449. Styger, Jos. Beitrage zur Anatomie der Umbelliferenfruchte. [Contributions on 

 the anatomy of umbelliferous fruits. ]TSchweiz. Apoth. Zeitg. 57: 183-188. Fig. 13-15. 1919. 

 —See Bot. Absts. 3, Entry 1698." 



2450. Taylor, William Randolph. On the production of new cell formations in plants, 

 (ontrib. Univ. Pennsylvania Bnt. Lab. 4: 271-299. PI. 71-78. 1919.— The author gives a 

 summary of previous work done on injecting chemicals into plant tissues. He experimented 

 Avith chestnut trees and various herbaceous plants by injecting into them distilled water, 

 chloroform water, ammonia, lithium carbonate, copper sulphate and picric acid, noting the 

 effect of the injection on the general growth of the plant and the tissue reactions. As a re- 

 sult of the experiments, he considers that all the elements of the normal stem are capable of 

 extensive multiplication unless they have been modified by cuticularization, lignification or 

 suberization. Cells that are collenehymatous are notwithstanding able to proliferate freely. 

 From these proliferated areas there may be formed cambioid zones that give rise to cork, to 



