1896. NOTES AND COMMENTS. 147 



some other explanation. It had been suggested that the light 

 absorbed by the colouring matter might be converted into heat, and 

 that the slight rise of temperature thus effected might perhaps be of 

 importance to the leaf. The genus Senecio, of world-wide distribution, 

 and varying from a small herb, like our wayside groundsel, to the 

 tree-like forms occurring on the several mountains of tropical Africa, 

 formed a good subject for the study of the adaptive variations occur- 

 ring among plants that were shown by the structure of the flowers 

 to be closely allied. Examination of the Indian Senecios threw 

 some light on the meaning of the hairy covering. Of the forty-two 

 species which might be classed as Himalayan, the great majority 

 were glabrous, while those found in the drier climate of the western 

 side of the peninsula were hairy, or showed some form of structure 

 generally associated with dry-growing plants. 



The lecturer finished by expressing a strong opinion on the great 

 value of descriptive botany for teaching purposes, and contrasting 

 the present position of students with that in which " the greatest of 

 our living systematic botanists " found himself in his own college 

 days. 



The Fertilisation of an Australian Wild-Flower. 



In his presidential address to the Philosophical Institute of 

 Canterbury, New Zealand, Professor Dendy, speaking of " Fertilisa- 

 tion of Flowers," refers to a common Australian wild-flower which is 

 somewhat remarkable in this respect. Stylidium is the largest genus 

 of a small family, almost exclusively Australian, to which it gives the 

 name Stylidieae. The species referred to is evidently Stylidium 

 gvaminifolium. The flowers are rather small and are borne on a stem 

 which springs from the midst of a tuft of grass-like leaves. Of the 

 five petals, four spread out in the form of a cross round the tube in 

 which the honey is secreted, while the fifth forms a small lip upon 

 which rests the slender column formed by the union of the stamens 

 and styles, and bearing at the end the anthers and stigma. Near the 

 tip, the column is bent upwards at a sharp angle. The anthers shed 

 their pollen before the stigma is fully developed, the flower thus 

 guarding against self-fertilisation. The bent portion near the tip of the 

 column is sensitive and is the part first touched by an insect, which, 

 visiting the flower in search of honey, pokes its proboscis down the 

 tube. No sooner is this spot touched than the column, which, owing 

 to a sharp bend at its base, is hanging out at one side of the flower, 

 springs over to the other side and brings the anther or stigma down 

 on the back of the insect, thereby attaching pollen to it, or remov- 

 ing some which has been brought from another flower. When the 

 insect has departed, the column resumes its original position and 

 awaits the next visitor, but when the flower has been fertilised it soon 

 loses its power of movement. 



This description recalls what may be seen in this country in the 



M 2 



