Oct., i9;2i.3 TAKAMINE:— LIFE HISTORY OF ISO ETES. 189 



place in one of them, the others degenerate ; in rare cases the 

 fertilization takes place in two or more of them and the embryos 

 develope up to certain stages. 



3. Near the nucleus of the egg cell, there appear sometimes one 

 or more rounded bodies, which stains with iron-alumhaematox\-lin 

 just as the nucleus, but the closer examination of their, structure 

 showed that the}^ are to be interpreted as chromatophores. 



4. Certain abnormalies in the formation of the ventral canal 

 cell and the egg cell have been described. 



5. In exceptional cases, macrospores and microspores are pro- 

 duced in one and the same sporangium. 



6. Diploid chromosome number of Isoetes asiatica is twentytwo, 

 and that of Isoetes japonica is fourtythree to fourtyfive, i. e., nearly 

 twice as that of the former. 



7. Hybrids o( 1. Japonicax I. asiatica as well as of/, asiaticax 

 I. japonica were raised, the further account of which is reserved for 

 the future. 



The present study has been carried on in the botanical laboratory 

 of the Science College, Tokyo Imperial University, under the direction 

 of Prof. K. Fujii, to whom I wish to express my best thanks for 

 his invaluable advice and criticism throughout the work. I am 

 also much indebted to Prof K. Shibata for his kind suggestions 

 given during the course of the study. 



Literature Cited 



]. Belajeff. Wi.. (1885) Antheridien und Sperniatozoiden der lieterosporen Lyco- 

 podiaceen. Bot. Zeit. Jahrg. 43. 

 ■ 1'. J, „ (1889) tJber Bau und Entwickelung der Sperniatozoiden der 



Gefiisskryptogaraen. Ber. der Deutsch. Bot. Gesell. Bd. VII. 



3. Campbell, D. H. (181)0-91) ContribiUion to the life history of Isoetes. Ann. 



of Bot. vol. V. 



4. ,^ „ (1890) Die ersten Keimungsstadien der Makrospore von isoetes 

 ecldnORporu Durieu. Be:', der Deutsch. Bot. Gesell. Bd. VIII. 



5. Ekstrand, H. (1920) Uber die Mikrosporenbildung von Isoeles echinospora. DuR. 



Svensk. Bot. Tidsk. Bd. XIV. 



6. Farmer, J. (1890) On Isioetes lacuslris, L. Ann. of Boi. vol. V. 



7. J, „ (1889) Preliminary note on the morphology and development of 



Isoetes lacusb-is, L. Ann. of Bot. vol. III. 



8. FuJii, K. (1907) Proceeding.s of the Tokyo Botanical Society, Bot. Mag. Tokyo. 



vol. XXI No. 242, p. (72) (Japanese); and the course of his university 

 lecture on Plant Morphology for the year 1911. 



