No. 2.] BRITISH ASSOCIATION MEETING. 151 



vious century. The result of this restoration became apparent in 

 the foundation of a new era in the knowleds-e of the minute cha- 

 racters of textureal structure, under the joint guidance of R. 

 Brown and Ehrenbers:, so as at hist to have entitled this branch 

 of inquiry, to its designation, by Mr. Huxley, of the exhaustive 

 investigation of structural elements. All who hear me are fully 

 aware of the influence which, from 1838 onwards, the researches 

 of Schwann and Schleiden exerted on the progress of Histology 

 and the views of anatomists and physiologists as to the structure ' 

 and development of the textures, and the prodigious increase 

 which followed in varied microscopic observations. It is not for 

 me here even to allude to the steps of that rapid progress by which 

 a new branch of anatomical science has been created ; nor can I 

 venture to enter upon any of the interesting questions presented 

 by this department of the microscopic anatomy ; nor attempt to 

 discuss any of those possessing so much interest at the present 

 moment, such as the nature of the organised cell or the properties 

 of protoplasm. I would only remark that it is now very generally 

 admitted that the cell wall (as Schwann indeed himself pointed 

 out) is not a source of new production, though still capable of 

 considerable structural change after the time of its first formation. 

 The nucleus has also lost some of the importance attached to it 

 by Schwann and his earlier followers, as an essential constituent of 

 the cell, while the protoplasm of the cell remains in undisputed 

 possession of the field as the more immediate seat of the pheno- 

 mena of growth and organisation, and of the contractile property 

 which forms so remarkable a feature of their substance. I cor- 

 dially agree with much of what Mr, Huxley has written on this 

 subject in 1853 and 1869, The term physical basis of life may 

 perhaps be in some trifling respect objectionable, but I look upon 

 the recognition of protoplasm, as a general term indicating that part 

 of the tissue of plants and animals which is the constant seat of 

 the growing and moving powers as a most important step in the 

 recent progress of histology. To Maechel the fuller history of this 

 in lowest forms is due. To Dr. Beale we owe the fullest investi- 

 gation of these properties by the use of magnifying powers be- 

 yond any that had previously been known, and the successful 

 employment of re-agents which appear to mark out distinction from 

 the other elements of the textures. I may remark, however, in 

 passing, that I am inclined to regard contractile protoplasm, 

 whether vegetable or animal, as in no instance entirely amorphous 



