120 



PRINCIPLES OF PLANT-TERATOLOGY. 



ochrea of the node above was split on the same side on 

 which the axillary shoot emerged just below it. This 

 may aptly be compared, as Prof. Oliver suggested, to 

 the disappearance of the posterior stamen in the flower 

 of Veronica as a result of fusion of the two lateral 

 posterior petals to form a single median posterior one; 

 but in the Polygon urn we see a kind of converse case, 

 in which, owing to the approximated and opposed 

 position of the shoot, the congenitally-fused stipules 

 become disunited on the self -same side. 



Conclusions. — All the phenomena coining under this 

 section are to be regarded as progressive and not 

 reversionary, for the changes are of the nature of 

 reduction, which appears to have been a main feature 

 of plant-evolution; although, of course, many of the 

 abnormalities mentioned are mere temporary lateral 

 deviations, and in no sense on the main line of evolu- 

 tionary change ; but they are all adaptations to changed 

 conditions, which are in some cases, probably in all, of 

 a purposive nature. 



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Berg. — " Einige Spielarten cler Fichte." Sitzb. Natttrf. Ges. 



Dorpat, Bd. viii, 1 (1886), pp. 157-163. 

 Carriere. — Traite generale des Coniferes, pp. 330-331. 



Paris, 1867. 



Gardeners' Chronicle, 1867, p. 654. (Robinia.) 



Caspary.— " Zwei Schlangentannen (Abies pectinata 13. C. 



f. virgata Casp.). ,; Bot. Zeit,, Jahrg. xl (1882), p. 778. 

 Chalon. — "Anomalie chez VAraucaria excelsa Carr." Bull. 



Soc. roy. hot. Belgiqne, vol. xlviii (1911), p. 231. 

 Clos. — " Cladodes et axes ailes." Mem. Acad. Sci. Toulouse, 



vol. v (1861), pp. 71-101. 

 " La Theorie des Sondures en Botanique." Loc. cit., 



ser. 8, vol. i (1879), pp. 107-146. 

 Danek. — " Morphologische unci anatomische Studien iiher die 



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z. Bot. Centralbl., Bel. xxix, Abt. 1, Heft 3 (1913), pp. 



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 Dobner, — "Ein astloses Ficlitenstammchen. /,; Flora, Bd.lv 



(1872), pp. 395-396. 



