96 ^ 
supposed, they arise from distinct structures or *' plastidia " present 
in the young cell from its earliest existence, and that any pigment, 
starch grains, etc., found in connection with the structure named 
arise by later changes produced by continuous growth and division 
of the few minute plastidia foun in the young cells. Those which are 
deeply seated and not as yet colored are called by Schimper 'Meuco- 
plastidia"; those which are nearer the light and in which a green 
coloring matter is developed, " chloroplastidia; " and those which in 
dividing give rise to needle- or' spindle-shaped bodies or triangular 
ones with sharply pointed corners, and pass through various shades 
from green to carmine-red, he calls '' chroraoplastidia.'* These forms 
appear to be due to the crystallization of certain of the proteid con- 
tents of the plastidia. All the plastidia of the stem and leaves appear 
to rise by division of the plastidia in the punctum vegetationis of the 
young stem, and those of the root from the division and differentia- 
tion of those of ihit punctum vegetationis of the radicle. As they are 
found at a very early age of the embryo, even when only eight cells 
old, as in Linuni Austriacum^ Schimper thinks it probable that they 
,arise from primitive plastidia in the oosphere. Starch grains may 
arise from the leucoplastidia, also, at a very early stage, as they may 
be observed in the oosphere. The Characeae would seem to be the 
earliest plants in which all three forms of these bodies occur, the 
apical cells containing leucoplastidia, and the antheridia owing 
their color to chromoplastidia. 
9 
Botanical Literature. 
Sylloge Fungorum omnium hucusque cognitorum. By P. A. Saccardo. 
The second volume of this work is now issued. It contains 813 
pages, besides 69 pages of Addenda, carrying the number of species 
up to 6,180, which is supposed to include all the Pyrenomycetes thus 
far knovvn. At the end this volume there is an alphabetical index of 
all the specific names in the two volumes; the generic name being 
added in parenthesis after each specific name. 
Whatever may be thought of the many new genera into which the 
old genus Spjmria is here divided, there can be but one opinion as 
to the practical value of the work, which should be in the hands of 
every thorough student of mycology. Vol. iii,, describing the "im- 
perfect " fungi, will appear next year, — J. B. E. 
Contributions to American Botany. XI. By Sereno Watson. Svo, 
pp, 100. (From the Proceedings of Amer. Acad, of Arts and 
Sciences. Vol* xviii). 
This instalment of Mr. Watson's Contributions to American 
Botany, issued on the rsth inst,, contains: (i) List of Plants from 
South-western Texas and Northern Mexico, collected chiefly by 
Dr. E. Palmer in 1879-80 ; Gamopetatal^ to Acotyledones ; and (2) 
Descriptions of some new Western species {Greggia linearifoliay 
Sagina crassicaulis^ Montia Howellii^ Astragalus Maithetvsii^ A. Win- 
gatanuSy A, hypoxylus^ Spircea occidentalism Ribes ambiguuniy Sedum 
radiatum^ Gayophytuni pumiluniy Eryngium discolory Suceda minuti- 
flora^ Eriogonum Shockleyi^ E. Havardi^ Euphorbia Flummerce^ 
Microsiyiis purpurea, Af. corymbosa, Allium Plummcrce and Bouteloua 
Texana.) 
