50 



Menthas, and Mr, Howard Shriver observed it in Nepeta heder- 

 acea^ which I can confirm, and I have seen also that it follows 

 the European Garden Thyme here to the same extent as in the 

 Old World. 



I want now to add another species to the list observed in the 

 Old World, though it is an Old World species from the moun- 

 tains of Caucasus — Nepeta grandijlora. I have two plants from 

 seed sent from Europe, showing the tendency is inherited. Ont 

 is hermaphrodite, the other (by abortion) purely pistillate. 



The case is specially interesting in view of the endeavor of 

 Mr. Darwin to detect differences accompanying the separate con- 

 ditions of the gyno-dioecious plants. (See Forms of Flowers, 

 Chapter VII). He seems to have noted little besides a greater 

 number of flower heads on the hermaphrodite, though there 

 were a greater weight of seeds from the female, in the case 

 of the thyme. The results are exactly the same in Nepeta 

 gra7idiflora. There are many more heads of flowers than 

 in the female, but in the hermaphrodite plant many flowers fail 

 to perfect and fall, while on the female apparently every flower 

 results in perfect seed. It is probable, therefore, that it is not 

 because the seeds are heavier in one than in the other, but be- 

 cause there are more perfect seeds though fewer heads. 



There is in these Nepetas a great difference in the plants. 

 The internodes in the hermaphrodite are one and one-half inches * 

 in the female there is but an inch between the nodes. This ten- 

 dency pervades the inflorescence, hence while the hermaphrodite 

 is loosely verticillately-spicate, In the female it is glomerate- 

 spicate. 



The flowers differ remarkably. They are almost inconspicu- 

 ous in the female, while worthy of the specific name grandijlora 

 in the hermaphrodite. They are about three times the size of 

 the female ones. 



The failure of some of the flowers to mature seed is not prob- 

 ably due to matters connected with poUinization. The pistils in 

 the hermaphrodites are evidently as perfect as those in the 

 female, and, as they are receptive only after their own pollen is 

 shed, they have the same chance to have pollen from neighbor- 

 ing flowers (though from the same plant) as the female has. It 



