THE AMERICAN NATURALIST [Vol. XLII 



We have a right to believe that fasciations, like other 

 monstrosities, with the exception, perhaps, of some cases 

 of virescence, 20 may be inherited, though not by all de- 

 scendants. Else such varieties could not be offered on 

 the exchange list of the Amsterdam botanic garden as 

 Aster Tripolium fasciatum, Geranium molle fasciatum, 

 Picris hieracoides fasciata, Veronica longifolia fasciata 

 along with Chrysanthemum segetum fistulosum, in which 

 the ligulate florets have become tubular like the disk 

 flowers, Dipsacns sylvestris torsus, which has a twisted 

 stem, Lychnis vespertina glabra, which lacks the tri- 

 chomes on the pod, etc. 21 But it must be remembered that 

 good soil, great care, especially in the earlier stages, 

 plenty of room— in one word, optimum conditions only- 

 give the desired result. 



Of far greater interest, at the present time at least, is 

 the consideration of the causes of fasciation and its exact 

 nature. Two kinds of fasciation appear to be possible. 

 The one is caused by the combination, in a plane, of sev- 

 eral axes, according to Lopriore. 22 The other mode of 

 fasciation, far more common, and the one which will be 

 considered here, consists of the flattening of the stem 

 through a broadening of its apical cone into a comb, as 

 shown by Nestler, 23 who did his work at the laboratory 



20 De Vries, Hugo. Een epidemie van vergroeningen. Avee un resume 

 en langue francaise. Bot. Jaarb. Dodoncea, 8: 66. 1896. 



In at least one case, that of the green-flowered Oxalis stricta, it has 

 been shown that virescence may be transmitted through the seed (18th 

 Ann. Eep. Missouri Botanical Garden, 99, 1907). The third observed, gen- 

 eration of these plants, now (January, 1908) in flower in the greenhouse, 



insects to which the cause of the virescence could be attributed. 



21 De Vries, Hugo. Erfelyke monstrositeiten in den ruilhandel der 



Dodoncea, 9: 62, 1897. 



"Lopriore, G. I caratteri anatomici delli radici nastriforme. Ex. in 

 Zeitschr. f. Pflanzenlcr., 14: 226, 1904. 



"Solche bandformige Nebenwurzeln entstehen entweder durch dichtes 



"Nestler, A. Untersuchungcn iiber Fasciationen. (Jester. Bot. Zeitschr., 

 44: 343, 1894. 



