H. M. FucHS 219 



Experiincnts are now in progress which are designed to give an 

 answer to the question of inheritance ; but the object of the work 

 described in Part I of this paper was to investigate thoroughly the 

 conditions under which self-fertilization occurs'. Besides this, the present 

 work deals with the effects of self-fertilization on the offspring. The 

 cause or reason of self-sterility is quite another problem and one which 

 is hardly touched upon here, although Section IV deals with a phe- 

 nomenon which may shed considerable light on the question. 



Starting with a race of Gioiia which was almost completely self- 

 sterile, the main object of Morgan's work was to investigate the cause 

 of this phenomenon and to bring about self-fertilization by artificial 

 means. Besides this he carried out an extensive series of cross- 

 fertilizations to discover whether eggs of one individual can be fertilized 

 equally well by the sperm of all other individuals, provided that it is 

 in good condition. He concluded that this does not take place. A 

 critique of Morgan's methods is given in the following section, showing 

 that the way in which the experiments were carried out does not justify 

 the conclusions drawn from them. It is not denied that there may be 

 different degrees of sterility exhibited in cross-fertilizations, but Morgan's 

 experiments do not at all prove the point. The only undoubted result 

 which Morgan seems to have established with regard to the self-sterility 

 is that self-fertilization can be induced to a certain degree by ti-eatment 

 of the sperm (and possibly also of the eggs) with solutions of ether and 

 alcohol. It is difficult to see, however, what light this sheds on the 

 cause of the .self-sterility. 



The preliminary experiments of the jjresent investigation brought 

 to light some interesting facts with regard to the manner of egg and 

 sperm deposition. The isolated animals lay some hundred of eggs 

 almost every day for a week or so, after which the frequency of the 

 depositions and the number of eggs laid decreases. Sperm is almost 

 always deposited simultaneously with the eggs, only rarely the one 

 being shed without the other. The manner in which the genital 

 products are ejected is as follows. A small mass of eggs exudes from 

 the aperture of the oviduct into the atrium, and at the same time a 

 small mass of sperm issues from the vas deferens. After about half 



' In connection with the phenomenon of self-sterility in Ciona, the following record of 

 a hermaphrodite Echinoid is of interest. In March 1913 a specimen of SlrongyloceiUrotus 

 lividus was kindly given to me by Dr Meyerhof, in which three of the gonads were ovaries 

 and in the remaining two the upper third was testis and the lower two-thirds ovary. 

 Both eggs and sperm were ripe and the specimen proved to be perfectly self-fertile. 



