(ae 
ie Se BOTANICAL GAZETTE 
[APRIL 
regions so widely separated, is an interesting problem in distribution — 
Jutia W. Snow, University of Michigan. 
*,,* The work upon which the foregoing paper is based was done in the 
spring of 1898, while the author held a fellowship given to the Botanical 
Department by Mr. D. M. Ferry, of Detroit. 
EXPLANATION OF PLATE VII. 
Fig. 1. Portion of a thallus. xX 300. : 
Fig. 2. Thallus in cross section. x 66. 
FiG. 3. Section at the center of a young thallus. X 875. 
FG. 4. Section at the margin of a young thallus. X 875. 
Fic. 5. Section through the center of an older thallus. X 300. 
Fig. 6. Portion of the surface of a disk ten days after removal from 
glass. X 300. 
Figs. 7, 8. Young thalli developing when attached to glass. X 875. 
Figs. 9-12. Young thalli when not attached to some solid substratum 
fig. 9, X 300; figs. 10-12, X 875. 
FiG. 13. Zoospores. X 875. : 
Fig. 14. Shape sometimes assumed by zoospores before liberation and 
occasionally retained after liberation. x 875. 
1G. 15. Zoospores arising directly from germinating zoospores. X 875: 
RECENT WORK ON THE LIFE-HISTORY OF THE 
RHOD OPHYCE#., 
In Oltmanns’ paper upon the life-history of the Rhode Ki 
have the most recent general expression of opinion on the are 
problems of sexual reproduction and the attendant phenomena baa 
development of the cystocarp found in this peculiar group . : and 
His is the fourth contribution attempting to cover a broad nai 
dealing with the questions in their totality as illustrated _ 
the entire class. The three papers that preceded his account $83 
Bornet and Thuret in 1867, Janczewski in 1876, and Schmitz ou . 
Of these three papers the first two gave descriptions of sai sa 
ogy and development of the cystocarps of several type: ig : 
clearness of expression and beauty of illustration, have work of 
passed. One can only express the greatest admiration a po is 
Bornet and Thuret, but their investigations, as also those of es uently 
came before the time of critical cytological study, and_consed 
Ree 
: I. oo. 1898- 
*Zur Entwickelungsgeschichte der Florideen. Bot. Zeit. 56° 99 
