32O T. H. MORGAN. 



cases showed that the eggs were equally good. The differences 

 are not so striking as in some of the other series. 



TABLE VIII. 



With the exception of c- and of d-sperm the sperm appears to 

 have been very poor in this series. The B, C and F-eggs were also 

 poor. It is noticeable that the results appear to depend in this 

 case more on the condition of the sperm than of the eggs. 



In my previous paper five tables, 1 similar to these, were given 

 for the dona found at Woods Hole. The incompatability was 

 less marked, although some cases, apparently of this sort, were 

 found. In general, however, the eggs crossed much more readily 

 than did the California form. Since the individuals at Woods 

 Hole were collected over a wider area than were those at Coro- 

 nado Beach, all of which grew on the same float, the chance is 

 greater that they may have had a different parentage. Whether 

 the closer descent may account for the greater incompatability in 

 the Coronado individuals can not be stated, but the facts are sug- 



gestive. 



DISCUSSION OF EXPERIMENTS. 



The most obvious question that suggests itself in those cases 

 where few eggs were fertilized is whether if more sperm was 

 added more eggs would segment. In answer to this I should 

 point out that an approximately equivalent amount of the same 

 solution containing sperm was added in each vertical series. 

 Another experiment made to test this point showed that the 

 amount added was many times greater than that necessary to 

 fertilize the eggs when a good combination is made. Thus 3, 6, 



1 A few errors in my former tables may be corrected here. Thus in all the 

 tables A c appears twice, and E a also. In experiment XIV. the first A e gave o per 

 cent., the second 100. This is due no doubt to the failure to add sperm to the first 

 lot, which might easily occur. This is apparently also the case in experiment XV. 

 In experiment XVI. the first E a gave only 5 per cent., the last 70. This difference 

 I cannot now account for. B' ; in this table should be B d , and C should be C e . 



