232 Mr. E. R. Lankester on the [Mar. 12, 



motor ideas), the sensory regions being looked upon as the organic seat 

 of ideas derived from sensory impressions. An explanation is attempted 

 of the phenomena of aphasia, and the relation of the memory of words 

 to the ideas they represent. 



The theory that a certain action, excited by stimulation of a certain 

 centre, is the result of a mental conception is considered and disputed. 

 From the complexity of mental phenomena, and the participation in them 

 of both motor and sensory substrata, any system of localization of mental 

 faculties which does not take both factors into account must be radi- 

 cally false. A scientific phrenology is regarded as possible. 



The paper concludes with a short consideration of the relation of the 

 basal ganglia to the hemispheres. The view is adopted that they con- 

 stitute a subvoluntary or automatic sensori-motor mechanism. 



March 12, 1874. 

 JOSEPH DALTON HOOKER, C.B., President, in the Chair. 



The Presents received were laid on the table, and thanks ordered for 

 them. 



The following Papers were read : 



I. " Contributions to the Developmental History of the Mollusca. 

 Sections I., II., III., IV." By E. RAY LANKESTER, M.A., 

 Fellow of Exeter College, Oxford. Communicated by G. 

 ROLLESTON, M.D., F.R.S., Linacre Professor of Anatomy and 

 Physiology in the University of Oxford. Received January 19, 



1874. 



(Abstract.) 



Section I. The ovarian Egg and early development of Loligo. 

 The points of greatest interest to which the author draws attention in 

 the present memoir are : 



1. The explanation of the basketwork structure of the surface of the 

 ovarian egg by the plication of the inner egg-capsule. 



2. The increase of the yelk by the inception of cells proliferated from 

 the inner egg-capsule. 



3. The homogeneous condition of the egg at fertilization. 



4. The limitation of yelk-cleavage to the cleavage-patch. 



5. The occurrence of independently formed corpuscles (the autoplasts) 

 which take part in the formation of the blastoderm. 



6. The primitive eye-chamber, formed by the rising up of an oval wall 

 and its growing together so as to form a roof to the chamber. 



7. The origin of the otocysts by imagination. 



8. The rhythmic contractility of a part of the wall of the yelk-sac. 



