Wild Forms and Species of Tuber-bearing- Solanums. 



PLATE 11. 

 Solanum etuberosum, Lindl. (Lilac-flowered Seedling.) 



A. Inflorescence and upper leaves, 



B. Flower showing anthers, x 2. 



C. Flower showing calyx, x 2. 



D. Flower, side view, x 2. 



E. Flower section, x 2. 



F, G, H. Cymes with flowers removed, 

 J. Pollen, x 300. 



PLATK 12. 

 POLLEN OF VARIOUS SPECIES OF Solanum. 



A, B, C. 



Figures representing the pollen-grains of Solanum verrucosum, Solanum polyadenium, 

 and Solanum tuberosum respectively, each x 300. Although varying somewhat 

 in size, the form in each case is regular and elliptical, and is typical of the pollen- 

 grains of all the wild types I have examined. 



D, E, F. Representing the pollen-grains of the cultivated potatoes " Up to Date," " Main- 

 crop," and " Discovery " respectively, each x 300. There is little if any 

 difference in the size of these three groups of pollen-grains, and in each case the 

 form is irregular and polygonal, and thus typical of the pollen of all the cultivated 

 potatoes I have examined. 

 Pollen-grains of Solanum etuberosum, x 300. 



Pollen-grains of a seedling plant bearing white flowers raised from a berry pro- 

 duced in 1906. The form of pollen-grains still remains regular and elliptical, 

 x 300. 



Pollen-grains of a seedling plant bearing white flowers raised from a berry pro- 

 duced in 1907. The form of pollen-grains still remains regular and elliptical, 

 x 300. 



J, K, L. 4 Pollen-grains of three seedling plants raised from berries produced in 1907, each 

 bearing lilac flowers. The form of pollen-grains in each case is irregular and 

 polygonal, corresponding to that of the cultivated potatoes, x 300. 



All pollen-grains shown in I, J, K, and L, were in each case from the flowers artificially selfed 

 under controlled conditions. 



The seedling plants which gave the pollen-grains shown in I and J were raised from the same 

 seed-berry. 



N.B. The figures of pollen-grains in this Plate, and of those also shown in the preceding 

 Plates, were drawn when the pollen-grains were dry. 



G. 

 H. 



I. 



