Junk, 1920] CYTOLOGY 279 



1925. Sampson, Arthur W. Suggestions for instruction in range management. Jour, 

 Forestry 17: 523-545. 1919.— See But. Absts. 3, Entry 2052. 



192G. Shinn, Harold B. [Rev. of: IIodor, C. F., and Jean Dawson. Civic biology 

 3S1 p. 166 fig. Ginn & Co.: Boston, 1918.] Plant World 21: 261-2G2. Oct., 1918. 



1927. TBAVER, Jay. How mother nature sows her seeds. Nat. Study Rev. 15: 247 



.9 fig. Sept., 1919. — Autumn is tlie time to study seed dispersion, which occurs: (1) by clastic 

 tissues (cranesbill, jewel-weed, violet, wisteria, witch-hazel, squirting cucumber, salvia); (2) 

 by water (water lily, cocoanut palm, dock, arrowhead, bladdernut, lyme grass); (3) by wind 

 (ash, elm, maple, linden, pine, milkweed, poplar, dandelion, smoke tree, clematis, button 

 wood, tumble weeds, small seeded fruits); (4) by animals (beggar's ticks, tick trefoil, cockle- 

 bur, burdock, avens, nuts, berries, etc., seeds carried by ants, by water birds, and man). — A. 

 Gundersen. 



1928. Yinal, YV. G. Mainly the pedagogy of seeds with some seeds of pedagogy. Nat. 

 Study Rev. 15: 213-232 2 pi. 1919. — Describes suggestive exercise with drawing of bur- 

 marigold seeds. Adaptations of dandelion. In study of seeds, seed coat, seed scar, seed 

 leaf, seed stem, seed bud and doorway (for micropyle) are suggested as simple names. Seed- 

 lings should be grown. Study of seed dispersal by wind, animals, mechanical contrivances 

 and water. — A. Gundersen. 



1929. Wells, B. W. Botany laboratory guide for elementary and general botany courses. 

 S3 X 16 cm. 40 p. Published by the author: Fayetteville, Arkansas, 1918. 



CYTOLOGY 



Gilbert M. Smith, Editor 



1930. Alvarado, Salustio. Sobre el verdadero significado del "sistema de fibrillas con- 

 ductor de las excitaciones en las plantas" de Nemec. (Un dato para la historia del condrioma 

 vegetal.) [True significance of Nemec's system of filaments for conducting stimuli in plants.] 

 Bol. R. Soc. Espanola Hist. Nat. 19: 147-152. 2 fig. 1919.— The author reviews Nemec's 

 article (Die Reizleitung und die reizleitenden Strukturen bei den Pflanzen, 1901) and points 

 out that the structures described and figured by Nemec are manifestly similar to the mito- 

 chondrial apparatus of vegetable cells discovered in Nymphaea alba by Meves three years 

 later. Nemec was able to obtain coloration of the filaments in his preparations of various 

 roots only for a very brief period immediately before death of the tissue and, according to 

 Guilliermond, this is true of the mitochondrial filaments also. The best observations of the 

 filaments were made from material fixed and stained almost exactly the same as the material 

 with which Meves later worked. Nemec observed the filaments particularly in the periblem, 

 and to some extent in plerome of rootlets of various plants, but almost never in the exterior 

 part of the periblem, the hypodermis, or the dermatogen. The filaments most clearly ap- 

 peared in those meristematic cells which are not dividing but are energetically enlarging and 

 have large vacuoles, the filaments there running in the longitudinal protoplasmatic trabeculae 

 and describing curves and loops and often closely approaching the nucleus. Alvarado points 

 out that this corresponds closely with the evolution of chondriomes in the root tips of beans 

 or chick-peas proximal to the growing point; first granules or short rods, then in young cells 

 of the pleroma transforming into chondriomes each time larger, until at the stage when 

 Nemec observed his filaments, the mitochondrial filaments are to be found following the trab- 

 eculae, curving or looping, and some of them passing near the nucleus. The sheath of Nemec's 

 filaments is no doubt the tonoplast which is to be seen at times either near the mitochondria, 

 the plastids, or the starch grains. Nemec subjected plants studied to diverse agents in order 

 to observe action of external conditions on the fibers, and the results are similar to those 

 obtained by authors who, like Guilliermond, have experimented on the chondriosomes: in 

 plasmolysis the filaments break up and finally disappear. The author believes that he has 

 demonstrated Nemec's filaments to be chondriosomes and that the claim that they are con- 

 ductive filaments is thus invalidated. — 0. E. Jennings. 



