190 



Mr. W. Heape. On the Germinal Layers [Dec. 22, 



quantity in charging, and for tension during discharge. Twenty such 

 boxes, one foot square, internal measurement, will give in series a 

 "battery of 500 pairs of one foot square plates. 



It will be seen from the foregoing that this method of conserving 

 energy has a wide field before it, and as it will benefit fellow- workers 

 in science, placing in their hands a means of experimenting with 

 powerful electric currents, I give it without reservation, freely and 

 untrammelled by patent rights, for their use. 



December 22, 1881. 



THE PRESIDENT in the Chair. 



The Right Hon. Sir William George Granville Venables Yernon 

 Harcourt, Knt., was admitted into the Society. 



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

 for them. 



The following Papers were read : — 



I. "On the Germinal Layers and Early Development of the 

 Mole." By Walter Heape. Communicated by F. M. 

 Balfour, F.R.S. Received November 30, 1881. 



The following is a note on some investigations which I have been 

 carrying on by the kindness and with the help of Mr. Balfour, in the 

 Morphological Laboratory, Cambridge, upon the origin and formation 

 of the germinal layers in mammals, more especially in the mole 

 (Talpa Ev/ropea). I hope shortly to be able to give a more complete 

 account. 



In the communication the following subjects are dealt with : — 



(1.) The origin of the epiblast. 



(2.) The mode of development of the mesoblast. 



(3.) The structure of the neurenteric canal. 



(4.) The relations of the mesoblast and the hypoblast to the noto- 

 chord. 



Recent investigations have left the earlier phases of mammalian 

 development in some confusion, it may therefore be advisable briefly to 

 mention the more important views which are entertained on this 

 subject. 



Professor Edward van Beneden, in a paper entitled " La formation 

 des feuillets chez de Lapin" ("Archives de Biologie," vol. i, Part 1, 



