26 Brannon. — The Strtuture and Development of 



SCHMITZ, Ft. Untersnchungen iiber die Befruchtung der Florideen. Sitzrngs- 



berichte der kon. Akademie der Wissenschaften zu Berlin, p. 220. 1883. 

 Davis, B. M. Development of the Frond of Champia parvula, Harv. from the 



Carpospore. Ann. of Bot., Vol. vi, 24. Dec. '92. 

 KucKUCK, Paul. Review of Oltmann's Ueber die Kultur- nnd Lebensbeding- 



ungen der Meeresalgen, Bot. Centralblatt, 51, 204-207. 1892. 

 Johnson, T. The Procarpium and Fruit in Gracilaria confervoides, Grev. Ann. 



Bot., Vol. i, Nos. Ill and IV. 



On SiDhaerococcus coronopifolius, Stackh. Ann. Bot., Vol. ii. 



OsTERHOUT, W. J. V. A simple freezing Device. Bot. Gazette, XXI, 195-201. 



Apr., 1896. 



EXPLANATION OF FIGURES IN PLATES I-IV. 



Illustrating Mr. Brannon's paper on Crinnellia americana, Harv. 



Fig. I. Transverse section of a frond, m, showing the region of the midrib. 

 /, the region of the frond which is only one layer of cells in thickness, x 125. 



Fig. 2. Transverse section of the holdfast, c, thick, yellowish cuticle, co, the 

 cortical portion of the holdfast, r, one of the rhizoidal filaments, x 725. 



Fig. 3. c, cystocarps borne on the distal end of the proliferations, x 30. 



Fig. 4. Two carpospores two days old showing a thick, cellulose cell-wall. 

 a, spherical spore before germination, and b, the spore having become elliptical 

 in outline shortly after the formation of an apical cell, x 500. 



Fig. 5. Three germinating carpospores showing gelatinous coats of cellulose 

 arranged concentrically, b, two-celled stage of germination, c and d, more 

 advanced and showing apical growth, x 500. 



Fig. 6. Carpospore four days old. b, a, a^ are the cells which are to produce 

 the foliar portion, and i' the cell which is to develop the holdfast portion of the 

 plant. X 500. 



Fig. 7. A tetraspore eight days after beginning to germinate, k, a filamentous 

 holdfast, c, the longitudinally arranged chromatophores, and v, the vacuoles. 

 X500. 



Fig. 8. Transverse section of a cluster of antheridia. d, a mother-spermatium- 

 cell with the protoplasm collected in its distal end. rf', showing the separation 

 of the young antherozoid. c, more advanced, and c^ a young antherozoid with 

 shining granular contents completely separated from mother-cell. (Haematoxylin 

 preparation.) x 1 200. 



Fig. 9. Surface-view of a patch of young antheridia {an). X325. 



Fig. 10. Portion of the marginal region of a young female frond showing 

 a three-celled cystocarp which is developing apically from a modified vegetative 



cell. X220. 



Figs. 1 1 and 1 2 show more advanced stages of Fig. 10. x 220. 



