620 EEPOET— 1889. 



anterior end of the antherozoid. The antherozoids of Muscineae (Musci and 

 Hepaticse), and those of Characeae, have only two very lonof and slender cilia attached 

 in the same position. The structure and mode of development of these organs are 

 almost identical in these two classes. 



In the Fucaceae, on the other hand, which may be taken as the highest type of 

 Algse with ciliated antherozoids, the structure of the antherozoid is altogether 

 dilierent. It is a naked cell, not enclosed in a cellulose-wall, with cytoplasm, 

 nucleus, and pigment-spot ; the two cilia both spring from a spot in close proximity 

 to the eye-spot, although one of them is attached to the body of the antherozoicl 

 for a portion of its length. 



The paper was illustrated by diagrams taken from the bpautiful work ori the 

 ' Development and Structure of Antherozoids,' by M. L. Guignard; and the im- 

 portance of the above facts was pointed out in support of the view that the 

 Characeaa are more nearly related to the Muscines than to the true Algje. 



6. A Eylrid Desmid. Bij Alfred W. Bennett, M.A., B.Sc, F.L.S. 



The author described the occurrence of what he regards as a hybrid form 

 between Euast7~um crassum, Ktz. and E. humerosum, Rail's. 



FRIDAY, SEPTEMBER 13. 

 The following Papers and Eeports were read : — 



1. Discussion on Acquired Characters. 



(a) On the supposed Transmission of Acquired Characters. 

 Bij B. B. Poulton, F.U.ti. 



(b) Feasible Experiments on the Possihility of transmitilng Acquired Hahits 

 by means of Inheritance. By Francis Galtox, F.B.S. 



Feasible experiments have yet to be designed that shall be accepted as crucial 

 tests of the possihility of a parent transmitting a cow/-/ew(Vff/ aptitude to his children, 

 which he himself possessed, 7J0f congenitally, but merely through long and distaste- 

 ful practice under some sort of compulsion. 



The requirements are to eliminate all possibility of parental or social teaching, 

 to bring up all the descendants in the same way, to make simultaneous experiments 

 on many broods during many generations, and, lastly, to economise time, money, 

 and labour. This list of requirements points with emphasis to experimenting on 

 creatures that are reared from eggs, as fowls, fishes, and moth?. Fowls— The 

 largely extending practice of hatching eggs in incubators for comuierclal purposes, 

 and the varied aptitudes of poultry, make them very suitable subjects. Birds are 

 said to have an instinctive dread of various insects; hence mimetic insects, that are 

 really good for food, are avoided by them. Do such insects exist, and could they 

 be easily reared, which poultry would avoid at first, though experience would 

 soon teach them to like and to eat greedily ? Similarly as regards sounds and 

 cries, which would frighten at first, but afterwards be welcomed as signals for 

 food, &c. Would the stocks of two breeders, one of whom adopted such experi- 

 ments as these and the other did not, differ in instinct after many generations? 

 Fish — The experiment (quoted by Darwin) of Mobius with the pike,"using a trough 

 of water divided by a glass plate into two compartments, in one of which was the 

 pike and in the other were minnows, was mentioned as an example. The pike 

 after dashing at the minnows many times, and each time being checked and hurt 

 by the glass plate, during some weeks, finally abandoned all attempts to seize them, 

 so that when the plate was removed the pike never afterwards ventured to attack 



