PROCEEDINGS OF THE SOCIETY. 89 



Difflugia and Euglypha, who have shown that foreign particles are drawn 

 into the interior of the protoplasmic body and stored in the fundus of 

 the shell, and are used, as necessity arises, in the growth or repair of the 

 shell, * a theory which we expounded in our paper read before the 

 British Association in 1913, and published in the Journal of fehia 

 Society, f The soundness of these deductions is brought within a reas< tri- 

 able probability of solution by the utilization of the methods which 

 Mr. Barnard has described. 



The third head is, of course, by far the most important, and is, I 

 am bold enough to say, epoch-making, and that is the vast question 

 of the structure, if not of the composition, of protoplasm — and when 

 I say of protoplasm I mean, of course, of living protoplasm. Pro- 

 fessor Arthur Dendy has summed up one side of this question in an 

 admirable sentence. He says : " It is difficult to form a satisfactory 

 idea of the chemical composition of protoplasm, because it is im- 

 possible to analyse it in the living condition ; indeed, in the living 

 condition it is constantly undergoing chemical change, and the moment 

 it dies it ceases to be protoplasm. "J The question of the structure of 

 protoplasm is one before which, to use a common phrase, the brain reels 

 and the senses gape. Our late President, Sir Ray Lankester, recently 

 told me a story which, if it has not been recorded elsewhere, is worthy 

 of record now. Some time in the early part of the latter quarter of 

 the last century, whilst attending a scientific Congress in Belgium he 

 was privileged and astonished to meet Theodor Schwann, the founder 

 of the cell theory,§ who was then a very old man, and indeed had 

 apparently retired from the scientific world for a great many years. 

 Sir Ray Lankester asked him what he had been doing in all those years 

 during which he had never been heard of, and Theodor Schwann told 

 him he had devoted the whole of his time and attention, with the 

 assistance of the most perfected processes and optical apparatus, to an 

 endeavour to establish the existence of any structure in protoplasm — and 

 that his investigations had been absolutely without result. No doubt 

 many Fellows of this Society are familiar with Dr. Biitschli's remarkable 

 work on this subject. || I am not going to digress upon the subject of 

 the alveolar nature of protoplasm set forth in that work, but in listening 

 to Mr. Barnard's observations it seems to me that if ever this problem is 

 to be solved, Mr. Barnard has indicated the road which leads to its solution. 



Again, Mr. Barnard has hardly more than touched upon the optical 

 methods employed with regard to the cutting off of certain rays of the 

 spectrum and the exclusive use of others. Who shall say that by the 

 utilization of these means we are not upon the threshold of the secret 

 of the chemical constitution of protoplasm itself ? To quote Professor 



* Verworn, 1888-90. Zeitschr. Wiss.iZool. Leipzig, xlvi. p. 455; 1. p. 443. See 

 also Minchin, " Introduction to the Study of the Protozoa," 1912, p. 35. 



t See this Journal, 1913, pp. 13-14. 



j A. Dendy, " Outlines of Evolutionary Biology," 1912, p. 22. 



§ " Microscopical Investigations on the Structure and Growth of Plants and 

 Animals " (Berlin 1839) Translation, Sydenham Society, 1847. 



l| O. Biitschli, " Mikroscopische Schaume," 1892. Translated by E. A. Minchin, 

 London, 1894. 



