570 Black: The imbedded antheridium in Dryopteris 



Literature 



c 



1. Campbell, D. H. '07. Studies on the Ophioglossaceae. Ann. Jard. 



Bot. Buitenzorg II. 6: 138-194.//. p-ip- 1907* 



2. Engler & Prantl, '02. Die natlirlichen Pflanzenfamilien 1*: 25. 



/. /^, A. B, 1902. 



3. Farmer, J. B. & Digby, L. '07. Studies in apospory and apogamy 



in ferns. Ann. Bot. 21 : 161-199. //. 16-20, 1907. 



4. Lang, W. H. '98. On apogamy and the development of sporangia 



upon fern prothallia. Phil. Trans. Roy. Soc. London, B 190 : 

 189-238.//. 7-1 J. 1898. 



5. Yamanouchi, S. '08, !• Sporogenesis in Nephrodiuuu Bot. Gaz. 



45: 1-30. //. 1-4, 1908. 



6. , '08, IL Spermatogenesis, oogenesis, and fertilization in 



Nephrodiian, Bot. Gaz. 45: 145-175. //. 6-8. 1908. 



7. — — , *o8, III. Apogamy in Nephrodiiun. Bot. Gaz. 45: 289— 



318.//. g, 10. 1908. 



Explanation of flsrures in plates 26 28 



All figures were drawn with the aid of a camera lucida, using homogeneous oil- 

 immersion objective 2 mm. combined with ocular 4. 



I-II. Dryopteris stipular is 



1. Two-celled stage of an imbedded antheridium in the apical sinus. 



2. Similar stage as above, the antheridium projecting slightly above the surface of 

 the prothallium. The two cells are more equal in size. 



3. Three-celled stage of an imbedded antheridium. 



4. Young stage In the development of an imbedded antheridium. Apical cell not 

 shown. 



5. Stage similar to that in fig. 4. Antheridium shows no projection from the 

 prothallium. 



6. Antheridium in the apical portion, showing slight shrinkage from the surround- 

 ing cells. Relative density of cells in antheridium and in the prothallium is seen. 

 Figs. I, 4, and 6 indicate the width of the cushion. 



7. Globular imbedded antheridium, causing a slight mound on the surface of the 

 prothallium. 



8. Wedge-shaped antheridium projecting deeply into the prothallium. Cytoplas- 

 mic contents of cells beginning to round up. 



9. Large mature antheridium, not projecting from the prothallium at all. Irreg- 

 ular outline of antheridium is seen. 



ID. Deep-seated antheridium in which only half has developed into sperms. The 

 other half consists of three large cells, one, that nearer the surface, resembling an egg- 

 cell. This antheridium is situated under two layers of cells. The cover of those 

 pictured In figs. 1-9 consists of but one layer of cells. 



II. Section showing two imbedded antheridia and a normal archegonium in the 

 apical region. The lower antheridium in the figure consists partly of sperm mother- 

 cells. The remainder is made up of four large cells. 



