Dec., 1910.] Self-Dividing Laminae of Certain Kelps. 
227 
LITERATURE. 
Kjellman, F. R. Laminariaceae in Pflanzenfamilien, I, 2. 1893. 
MacMillan, C. Observations on Nereocystis. Bulletin Torrey 
Botanical Club, 2G. 1899. 
Oltmanns, F. Morphologie und Biologie der Algen, I. 1904. 
Reinke, J. Studien zur vergleichende Entwickelungsgeschichte 
der Laminariaceen. Kiel. 1903. 
Rosenthal, O. Zur Kenntnis von Macrocystis und Thalassio- 
phyllum. Flora 43. 1890. 
Setchell, W. A. Classification and Geographical Distribution 
of the Laminariaceae. Trans. Connecticut Acad. 9. 1893. 
Skottsberg, C. Zur Kenntnis der Subantartischen und Antar- 
tischen Meeresalgen. I. Phaeophyceen. 1907. 
Sykes, Miss M. G. Anatomy and Histology of Macrocystis 
pyrifera and Laminaria saccharina. Annals of Bot. 22. 1908. 
Fig. 1. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Fig. 12a 
Fig. 13. 
Fig. 14. 
Fig. 15. 
Fig. 16. 
Fig. 17. 
Fig. 18. 
Fig. 19. 
Fig. 20. 
EXPLANATION OF PLATES. 
A Young Nereocystis plant showing splits and splitting lines. 
Cross section of Nereocystis lamina at a point corresponding to 
to Fig. 1, a. 
Cross section of Nereocystis lamina at a point near end of split 
corresponding to Fig. 1, b. 
Cross section of Nereocystis lamina showing mechanical tear. 
Cross section of a newly divided lamina of Nereocystis showing 
wounds. 
Healing lamina of Nereocystis. 
Healing lamina of Nereocystis, later stage. 
Completely healed lamina of Nereocystis. 
Cross section of normal Postelsia lamina. 
Middle stage in splitting Postelsia lamina. 
Final stage in splitting lamina of Postelsia. 
Last stage of splitting in Lessoniopsis. 
Entire section showing position of Fig. 12. 
Origin of perforation in Macrocystis, middle stage. 
Structure of portion enclosed in dotted line, Fig. 13. 
Final stage in the development of the original perforation in 
Macrocystis. 
First stage in the advance of the mature cleft in the Macrocystis 
lamina. 
Primary cortical meristem in splitting region of Dictyoneuron. 
Secondary cortical meristem within the first in Dictyoneuron. 
The cleft and fan shaped structure developed in the splitting of 
the Dictyoneuron lamina. 
Final stage in the dividing process in Dictyoneuron. Cortical 
meristem present. 
