1892.] Mr Willis, On Gynodioecism in the Labiatae. 



349 



Corresponding variations on the normally female plants were 

 of much rarer occurrence. Occasionally, however, I found a female 

 plant bearing a large hermaphrodite flower among the females, 

 and flowers with one or two stamens also occurred. 



That these variations are not simply due to cultivation appears 

 from the fact that they are as common upon the wild form, which 

 I have examined at Abington (Cambs.) and Llangollen. Three 

 batches of plants gathered at the same time in August, 1890, gave 

 the following results : 



A. Plants from the "Labiatae" bed, Bot. Gardens, Camb. 



B "Medicinal" 



C Abington (Cambs.) 



The numbers in columns I., II., III., IV., represent the numbers of flowers with 

 1, 2, 3, 4 aborted stamens, respectively. 



It will be noticed that the number of flowers fully female is 

 greater than the number of any of the intermediate forms, and 

 this I found to be always the case, if a considerable number of 

 plants were examined. Some of the variations were very striking, 

 e.g. on each of two plants in batch A there occurred a lateral 

 twig which bore female flowers only. I have observed the same 

 phenomenon on two or three other occasions. 



Similar variations occur upon the hermaphrodite plants of 

 other Labiatae. Miiller*, Schulz-|-, and others have observed them 

 in some, and I have myself noticed them in Thymus serpyllum, 

 Nepeta Glechoma, and N. Gataria (all in the wild state), besides 

 many garden plants of the order, e.g. Micromeria Juliana, Nepeta 

 longijlora, Hyptis pectinata, Bystropogon punctatus, Mentha crispa, 

 Satureia hortensis and S. montana. The last-mentioned is ex- 

 tremely variable, at least in Cambridge, more than half the flowers 

 usually departing from the normal type. 



During 1891 various observations were made upon these 

 abnormalities, with a view to discovering the conditions govern- 

 ing them, and also to throwing some light upon the origin of 



* '• Fertilisation of Flowers," Eng. Ed. p. 476 (Galamintha Glinopodium). 

 \ "Die biologischen Eigenschaften von Thymus Chamaedrys Fr. u. T. angusti- 

 folius Pers." Deutsche Botan. Monatsschr. in. 1885, p. 152. 



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