412 - BOTANICAL GAZETTE [june 



the silicified form we have had many records of archegonia from Brong- 

 NiART^ and Renault. 7 The latter devoted considerable time and attention 

 to palaeozoic bacteria, and was the first to record tissue formation in a 



gram 



preserved 



megaspores of the Lepidodendreae, and recently ScottS has recorded the 

 early stages in the germination of fern spores. Still more recently I have 

 had occasion to record a very early stage in the development of the embryo 

 sac in the young megasporangium of Miadesmia.^ But even with instances 

 such as these, we should not have ventured to identify these antherozoids 

 if it had not been for the antecedent discovery in Ginkgo and the cycads 

 of this type of male gamete. As students of phylogeny, we may well con- 

 gratulate ourselves that such forms as Ginkgo biloba and Microcycas calo- 

 coma persist to the present time to interpret to us the elaborate pollen 

 chambers of the palaeozoic era. In their turn these paleozoic structures 



of male gamete 

 University. 



great antiquity of the cycad typ' 

 Royal Holloway College, London 



THE EMBRYO OF CERATOZAMIA: A PHYSIOLOGICAL STUDY 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY III 



(with seven figures) 

 Ceratozamia is a genus of cycads of the American tropics. Its 

 habit and habitat and the manner in which the ovules are shed shortly 



Chamberlain 



structures 



The embryo has only one cotyledon. This fact was observed by Van 

 liEGHEM (2) as early as 1873 in a form which he considered a hybrid 

 between C. longijolia and C. mexkana, but which was probably pure C. 

 longtjoha. In 1878 Warming (^) recordeH fhp m^nnr^f.ri^^^n.^,ic r^nrlltlnn 



arises 



Of the h>-pocotyl axis and little by little comes to surround it. 



Bemg engaged in an anatomical study of the seedling, the first obser^-a- 

 tion^I made was naturally upon this character. In every case in over one 



^ Brongnl^t, a., Recherches sur les graines fossiles siHcifies. Paris. iSSi. 



NewPhjtol. 5:170-172. 1906. 



"Bexsox, Margaret, Jk 

 a seed-like structure, Phil. 1 

 1908. 



m. Paris. 1896 

 germinating spo 



