Studies of Teratological Phenomena. 75 



Fasciations (perhaps produced in this manner) of Solanum lyeo- 

 persicum, Antirrhinum majus, Echeveria glauca and others have been 

 propag-ated by cuttings at the Missouri Botanic Garden (Hus 1908). 



Eeed (1912) induced fasciations in seedlings of Phaseolus multi- 

 florus through the removal of the plumule when it was about an inch 

 long. Shoots were thus caused to develop from the axillary cotyledon 

 buds, and many of them showed fasciation. The removal of the apical 

 buds from these shoots caused still more fasciated and twisted structures 

 to delelop. Through this treatment, the hypocotyl also often became 

 fasciated. Vicia fdba and Pisum sativum under the same treatment as 

 P. multiflorus produced only a few slightly fasciated structures. 



Epigeal t}T^)es such a Phaseolus vulgaris, Lupimis douglasii, Ricinus 

 communis and Cucurhita pepo have fleshy cotyledons, and hence a 

 large supply of reserve food. When subjected to the same treatment 

 as P. multiflorus, no fasciations were produced. Epigeal-tj^oe seedlings 

 were given a plentiful supply of nitrogenous manures, and some were 

 mutilated. Although the checks were \igorous in their growth, the 

 mutilated individuals did not produce any fasciated structures. 



Daniel (1904) induced fasciation in the common European pear 

 by a method of pruning called "ä onglet complet", which consists 

 of removing all the buds, the terminal included, from a branch, and 

 allowing tliis branch to remain on the tree. 



D. Discussion and summary of Parts B and C. 



All characters, whether somatic or otherwise, may be regarded as 

 the resulting expressions, in an organism, of stages in the development 

 of a factor (gene, or germinal unit) plus the modifications of this 

 expression brought about through the presence in the organism of other 

 factors, and through the action of external environmental conditions such 

 as soil, climate, insect depredations, etc. 



Fasciation, on the basis of this conception of a character, may be 

 caused by man}^ diverse and unrelated combinations of internal factors 

 and external conditions. Hence, to speak of it as latent, when it does 

 not exist as an observable entity, is an absurdity. If one holds to such 

 a vague form of interpreting certain facts, the furniture dealer is justified 

 in speaking of chairs being latent in mahogany trees or of the latency 

 of office desks in oak trees. The fore-going data show us beyond all 

 doubt that many factors, both internal and external, are responsible for 



