10 The Botanical Gazette. [January, 
group of cells, and added that the root-cap was from sister — 
cells separated from the epidermis. To the meristematic 
epidermis he gave the name of dermatogen. In 18701° he’ 
confirmed this first assumption in a paper, the conclusions of — 
which were quite generally accepted at the time. According — 
to him the cortex and central cylinder each has an initial 
group of its own, and the root-cap is derived from the epi- 
dermis, one being able to trace it for a certain distance under 
the root-cap. He completely exploded Niageli’s theory of a - 
single apical cell for phanerogams, but he fell into an error 
similar to Nigeli’s in supposing that all phanerogams followed _ 
the type explained above. Hanstein was followed by a pupil — 
of his, Reinke, who, by the study of mature roots, confirmed 
Hanstein’s conclusions, Hanstein’s studies having been made 
on the roots of embryos. Although Reinke examined but — 
few roots, and all of those of angiosperms, he ‘held that all — 
phanerogams had the structure of the one species especially — 
examined, that is Helianthus annuus. Reinke admitted — 
some variations from type, but held that these were not of 
enough importance to found a new t e. 4 
Prantl*? opposed Reinke’s general statement, saying that — 
in maize the epidermis was distinct from the root-cap, pos: 
sessing an initial group of its own, and in Pisum and Vicia — 
ee 
dermatogen, but from the periblem, or perhaps that the root- 
Cap was absent and that the cortex served its purpose, bein 
thrown off and developing again. 
About the same time Strasburger!# published a memoir 1 
which he held that all Contfere, Gnetacee and Cycade@ hav 
the structure made out for Pinus pinea. Reinke admitted tha 
this was probably true. The appearance of doubtful case 
has made uncertain the acceptance of Hanstein and Reinke’ 
theory of one type of meristem structure for the roots of all 
'°Die Entwickl i i : , 
Abhandl aus d, Goblets der Morphologic soa otal eee TO 
"tUntersuchungen iiber W i 3 
' achsthumgeschichte und Morphologie der 
erogamenwurzel. tan. Abhandl., etc., mu, 1871. : : 
1? Regeneration d : é 
Bot. Instituts Wiirzb, bea Shiapiiceaiaed an Angiospermenwurzeln. Arb. 
*SBot. Zeit. 1872, 
*4Die Coniferen und Gnetaceen. 
Jena 1872. 
