260 BOTANICAL GAZETTE [ocrosss 
root-cells, from which spring rhizoids terminating in multi- 
cellular disks. Others originate in the cell adjacent to the basal 
cell and in the cortications. In addition the first two possess a 
strengthening mass of intracuticular root-fibers, but Ceramiumis 
quite destitute of them. 
Thus, while of some value in showing relationships, it will 
be seen that the chief interest ina comparative study of the devel- 
oping spores and holdfasts of the Florideze would be in varia- 
tions dependent upon differences in light, temperature, or the 
density of the surrounding medium, and in adaptations to vege 
tative reproduction. 
In closing, I would acknowledge my indebtedness to Dr. 
Setchell, who, in 1895, suggested the holdfasts of the Rhodo- 
phycez as a subject that would repay investigation; to the late 
Dr. Humphrey, under whose helpful and suggestive direction the 
work described in this paper was practically begun; and to 
Professor Penhallow for kind advice. 
McGILL UNIVERSITY, MONTREAL. 
LITERATURE REFERRED TO. 
1. BorGe, O.—Uber die Rhizoidenbildung bei einigen fadenforms® 
Chlorophyceen. Upsala, 1894. 
2. BRANNON, M. A.—The structure and development 
americana Harv. Annals of Botany 11:1. 1897. 
of Grinnellia 
BREBNER, G.—On the origin of the filamentous thallus of Dumontis a 
filiformis. Jour. Linn. Soc. 30: —. 1895. Har. 
4. Davis, B. Mi— Development of the frond of Champia parvult 
from the carpospore. Annals of Botany 6 : 339. 1892. “is 
5. Gipson, R. J. H.— Notes on the histology of Polysiphonta 
(Roth.) aie. Jour. of Bot. 29: 129. 1891. 
6. OLTMANNS, Fr.— Uber die Cultur- und Lebensbedingunges 
Meeresalgen. Jahrb. fiir wiss. Bot. 23 : 349. 1892. 
ca tener J. AE 
7. OsTERHOUT, W. J. V.—On the life-history of Rhabdonta 
Annals of Botan : + 1866. 
any 10: 403. 189 torgane det : 
8. STROMFELT, H. F. G.— Untersuchungen iiber die Haf 
Algen. Bot. Centralbl. 33 : 381. 1888. 
Sai TRS OT is dee a in Rs. 0 ASR ales 
