THE EMBRYO-SAC OF AGLAONEMA lOI 



inflorescences are produced very freely, forming a sympodium. 

 The spadix, which is some 5 to 6 centimetres in length, is 

 enclosed in a white open spathe of about the same length. 

 Several years ago the writer investigated a species of 

 Aglaonema which was cultivated in the Hope Botanical 

 Gardens of Jamaica, where it was grown under the name of 

 Dieffe7ibachia Aglaonema. This plant much resembled A. 

 commutatum, Schott, but may not have been that species. 

 Several puzzling features were found in the development of 

 the embryo-sac, but the material was not complete enough to 

 make clear the nature of some of these. 



Sometime later, specimens of A. covimutatiini were procured 

 at Kew, and these much resembled the specimens collected 

 in Jamaica, although there were some differences. While 

 the preparations from this species added materially to our 

 knowledge of the genus, there were still a number of points 

 which remained obscure. 



In 1906, while working at the famous botanical gardens of 

 Buitenzorg in Java, the writer again had an opportunity of 

 collecting further material which included two species, A. 

 viodestuin, Schott, and A. simplex, which were growing vigor- 

 ously in the garden, and an investigation of this material has 

 made pretty clear what seems to be the normal development 

 of the embryo-sac. The details of fertilisation, however, 

 could not be satisfactorily made out, and the early history 

 of the embryo still needs further investigation. A re- 

 examination was also made of the preparations of A. 

 commutatum and A. pictum, collected at Kew, and also the 

 West Indian specimens, for comparison with the Javanese 

 species. 



The flowers in Aglaonema are monoecious and are arranged 

 much like those of the common Calla lily, but the pistillate 

 flower, which is composed of a single carpel, contains only 

 one large ovule. The pistillate flowers are at the base of the 

 spadix, the upper part of which is composed of the densely 

 crowded staminate flowers. As in many other Arace^, the 

 pistillate flowers mature before the staminate ones, thus 

 ensuring cross-pollination. There was strong evidence that 

 the ovules might develop without fertilisation, but further 

 investigations will be necessary before it will be safe to 



