1892.] Mr Willis, Ov Oynodioecism in the Labiatce. 19 



exactly resembled the wild ones, the rest had flowers of very 

 various sizes, and the rudimentary stamens were in most cases 

 large and light-coloured. They also differed from the wild form 

 in the time of opening of the stigmas. In the wild plant the 

 stigmas separate shortly after the opening of the flower, and so 

 the female flower differs considerably in this respect from the 

 very protandrous hermaphrodite. One of the seedling females 

 resembled the wild form in this respect ; the rest differed from it 

 in various degrees. Their stigmas did not open until some time, 

 occasionally as much as two or three days, after the opening of 

 the flowers. They seemed in fact to have recently arisen from 

 hermaphrodites, and to have retained, though now useless, or even 

 disadvantageous, their protandry. 



These and other peculiarities, besides their greater yield of 

 abnormal flowers, led to the idea that possibly some, at any rate, 

 of these female plants had sprung, not from the hermaphrodite, 

 but from the female flowers, upon the parent plant. Experiments 

 to test this point are now in progress. 



The variation of the numbers of flowers of each kind on one 

 of these seedling females was very remarkable. Seedling B at 

 the end of the first week, bore 7 abnormal flowers, out of a total 

 of 42, and of these 4 were hermaphrodite. At the end of the 

 third week there were 3 abnorraals (no hermaphrodites) in 31, 

 and at the end of the fourth week 25 abnormals (22 hermaphro- 

 dites) out of only 32 flowers ! Eleven of the hermaphrodites 

 occurred on a lateral branch of the inflorescence, which bore no 

 other flowers. [Of the case of the hermaphrodite plants in the 

 previous paper*.] 



Experiments are now being set on foot to determine the relative 

 fertility of the various types of flower, normal and abnormal, and 

 also to discover the type of offspring to which each gives rise, 

 besides other points. 



From the observations on the hermaphrodite plants it seemed 

 possible that the presence of abnormal flowers might be due 

 directly to lack of nutriment, as they were most common on the 

 lateral twigs of the inflorescence. An attempt was made to test 

 this as follows. A string was tied tightly round the main axis of 

 the inflorescence, about the middle, ten days before it began 

 flowering. Only one of the plants thus treated survived in a 

 healthy condition, but the results obtained seemed to favour the 

 view expressed above. The number of abnormal flowers above 

 the string was large (17 in 137), that below was small (1 in 98). 

 Further observations will be made upon this point. 



F. Mowes-|- has given instances observed by him of abnormal 



* I. c. p. 350. 



t "Ueb. Bastarde von Mentha arvensis n. M. aquatica, sowie d. sexuellen 



2—2 



