58 



Anniversary Meeting. 



[Nov. 30, 



actual detail, and of which it must be remarked that while the 

 interest and beauty of the researches are beyond question, caution 

 must be exercised in accepting the mechanical speculations by which 

 Strasburger attempts to explain them. He has himself shown that 

 cell-division presents the same phenomena in the animal kingdom ; a 

 result which has been confirmed by numerous observers, amongst 

 whom I may content myself with mentioning one of our own Society, 

 Mr. F. Balfour. Strasburger further points out that this affords an 

 argument for the community of descent in animal and vegetable cells ; 

 he regards free cell-division as derivable from ordinary cell-division 

 by the suppression of certain stages. 



Turning now to the discoveries made during the last five years in 

 Physiological Botany, we find that no one has advanced this subject so 

 greatly as Mr. Darwin. In 1875 was published his work on Insectivo- 

 rous Plants, in which he ascertained the fact that a number of species 

 having elaborate structures adapted for the capture of insects, utilized 

 the nitrogenous matter which these contain as food. The most impor- 

 tant principle established in the course of these researches was, that 

 such plants as Drosera, Dioncea, Pinguicula, secrete a digestive fluid, 

 which has led through Gorup Bezanez's investigations on the ferment 

 in germinating seeds, to a recognition of the active agency of ferments 

 in the transmission of food-material, which marks a great advance in 

 our knowledge of the general Physiology of Nutrition. 



The extreme sensitiveness of the glands of Drosera to mechanical 

 and chemical stimulus (especially to phosphate of ammonia), the 

 directive power of its tentacles, depending upon the accurate trans- 

 mission of motor impulses, and the "reflex" excitation of secretion 

 in the glands, were all discoveries of the most suggestive nature in 

 connexion with the subject of the irritability and movements of plants. 

 The phenomenon of the aggregation of the protoplasmic cell-contents 

 in the tentacles of Drosera is a discovery of a highly remarkable 

 nature, though not yet thoroughly understood. Lastly, Mr. Frank 

 Darwin, following his father's footsteps, as it were crowned the edifice 

 by showing to what an extent insectivorous plants do profit by nitro- 

 genous matter supplied to their leaves. 



In close relation to these researches are those, also by Mr. Darwin, 

 on the structure and functions of the bladder of Utricularia, which he 

 has shown to have the power of absorbing decaying animal matter ; 

 and those of Mr. Prank Darwin on contractile filaments of extra- 

 ordinary tenuity attached to the glands on the inner surface of the 

 cups formed by the connate bases of the leaves of the Teasel, which 

 filaments exhibit motions suggesting a protoplasmic origin. It is to be 

 hoped that their discoverer will pursue his investigations into these 

 curious bodies, whose origin and real nature in relation to the plant 

 and its functions are involved in obscurity. 



