1774 



Journal of Applied Microscopy 



The preliminary notes on these important discoveries first appeared in Japanese,^ 

 being immediately followed in German ^ and English.-^ 



In the following year the occurrence of spermatozoids in Zatfiia was announced 

 by Dr. Webber,* an American botanist. In 1900 the presence of spermatozoids 

 '\\\ Stangeria paradoxa, another Cycad, was proven by an Englishman, Dr. Lang.'^ 

 These discoveries may be looked upon as a partial fulfillment of the wise prophecy 



of that noted German botanist Hof- 

 meister,'' who predicted more than fifty 

 years ago the possible discovery of sper- 

 matozoids in Gymnosperms. 



On the 9th of September, 1896, Mr. 

 Hirase for the first time observed living 

 spermatozoids of Ginkgo coming out from 

 the pollen-tube. He was able to study at 

 that time only two of them, which are fig- 

 ured in his full paper." He described the 

 spermatozoid as an oval body, S2/i long 

 by 49/i wide, with a spiral marking, bear- 

 ing numerous cilia on the upper end, a 

 tail 2S/^ in length on the other end, and 

 having a large nucleus in the center 

 completely surrounded by the cytoplasm. 

 The cilia on the .spiral band being 

 homologous to the tail of many animal 

 spermatozoids, the so-called tail of the 

 Ginkgo spermatozoids can not be homo- 

 logized with any structure found in either 

 animal or plant spermatozoids. Moreover, Dr. Webber has not seen any tail-like 

 appendage in the spermatozoids of Zamia, and there was some hesitation among 

 botanists in accepting the form described by Mr. Hirase as a normal one. 



Our knowledge of the spermatozoids of Ginkgo remained in the same condi- 

 tion until September, 1898, when several Japanese botanists, including myself, 

 made somewhat careful studies of them. In about a week, we examined several 



FiG- 



The same tree in winter. 



1. Hirase, S. — On the spermatozoid of Ginkgo biloba. Bot. Mag. Tokyo, 10: 325-328, 

 Oct., 1896. 



Ikeno, S. — The spermatozoid of Cycas revoluta. Bot. Mag. Tokyo, 10: 367-368, Nov., 

 1896. 



2. Hirase, S. — Untersuchungen iiber das Verhalten des Pollens von Ginkgo biloba. Bot. 

 Centralbl. 69: 33-35, 1897. 



Ikeno, S. — Vorlaufige Mittheilung iiber die Spermatozoiden bei Cycas revoluta. Bot. 

 Centralbl. 69: 1-3, 1897. 



3. Ikeno and Hirase. — Spermatozoids in Gymnosperms. Ann. Bot. II: 344, 1897. 



4. Webber, H. J. — Peculiar structures occurring in the pollen-tube of Zamia. Bot. Gaz. 

 23: 453-458, 1897. 



The development of the antherozoids of Zamia. Bot. Gaz. 24: 16-22, 1897. 



5. Lang, W. H. — Studies in the development and morphology of Cycadean sporangia. II. 

 The ovule of Stangeria paradoxa. Ann. Bot. 14 : 281-306, 1900. 



6. Hofmeister, W. — Vergleichende Untersuchungen der Keimung, Entfaltung und Frucht- 

 bildung hoherer Kryptogamen und der Samenbildung der Coniferen. Leipzig, 1851. 



7. Hirase, S. — fiiude sur la fecondation et I'embryogenie du Ginkgo biloba. Second 

 memoire. Jour. Coll. Sci. Imp. Univ. Tokyo, 12: 103-149, 1898. 



