602 Transactions. 



short thick filaments and two anther-lobes as in the stamens of the male 

 flower. Certain cells are seen, under the microscope, to form mother cells of 

 the pollen-grains but in no case examined were actual pollen-grains formed. 

 The gynoecium in the female flower consists, as in the male flower, of 

 two carpels each with a single ovule and two style-arms. Sometimes buds 

 with three carpels are found. The ovary is then triangular, with slight 

 depressions between the ridges. In the flowers with two carpels the ovary 

 is compressed. In one tree observed the buds and fruit" were mottled, 

 green and brown, while in all others they were brown, the colour being 

 constant for each tree. 



Opening of Flower. 



When the flower is about to open, one of two methods is adopted : either 

 the perianth is shed without opening as a cap — that is almost invariable in 

 the mottled variety — or the petals may open as in'the male flowers. Enclosed 

 within the perianth-cap thus shed are the staminodes. When the petals 

 are spread they do not persist, the typical flower consisting only of sepals 

 and the gynoecium. The two stigmas diverge shortly after the flower 

 opens, and the petals are smaller than those of the male flower. In the 

 female flower there is no scent ; nor have any insects been seen visiting the 

 flowers in search of nectar or pollen, though nectar is produced in small 

 quantities. Occasionally there are three carpels, with the corresponding 

 styles and stigmas. The ovary is then triangular. Intermediate stages 

 were often noted in which there were three carpels, but only two well-formed 

 styles, the third being nearly abortive. In others, again, only two carpels 

 were formed, with their respective styles, occupying positions as in the 

 trilocular ovary. This seems to bear on the gradual evolution of the 

 V 'mbelliferae among the Archichlamydeae making for combined simplicity 

 of structure and effectiveness in achieving pollination. 



An article on " Floral Evolution " which appeared in the New Phyto- 

 logist, vol. 10, April, 1911, p. 113, points out the importance of progressive 

 reduction in the number of ovules in each carpel. In U mbelliferae the climax 

 of economy is reached in the invariable production of one ovule only for 

 each carpel. The article goes on to show the importance of floral aggrega- 

 tion in economy, and also of the inferiority of the ovary. In the matter of 

 aggregation and in bicarpellarity of the ovary Nothopanax seems to mark 

 an advance on another member of its order, Scheffiera digitata. In the 

 matter of insect- visits it does not appear to have attained any distinction. 



In the female flower of Nothopanax arbor eum the disc may grow up as 

 a conical structure, but usually it remains more or less flat. Pollen-grains 

 have been seen on the stigmas and in the axils of the pedicels and peduncles. 

 In some ^ases the grains were undoubtedly those of Nothopanax arboreum, 

 but in no case was a pollen-grain seen to germinate. No nectar is produced 

 in the conical-disced flowers ; there is, therefore, little or no apparent 

 reason why insects should visit the flowers. 



The plant is the food plant of the caterpillar of a moth, Declaim 

 artronivea. This caterpillar is mottled like the fruit among which it lives, 

 and is therefore protected from attack, being very difficult to detect. On 

 the trees bearing brown fruit a very similar brown caterpillar was found. 

 Being unable to move from tree to tree, the caterpillar cannot assist in 

 pollination. 



All the flowers of the inflorescence are of the same value and structure 

 both in male and in female plants. In this respect Nothopanax differs 



