158 



taceous are nearly all woody plants with scalariform vessels. 

 Further, evidence from plant serums may be looked upon as of 

 significance, without considering it as all-conclusive. Also the 

 fact that leaf -eating insects may choose related species for their 

 attacks is significant; it looks as if insects discovered plant 

 families before the botanists. Similarly, plant pathology shows 

 us that fungous parasites often select host plants of related 

 forms. 



"Characters must be weighed rather than counted," said 

 Bernard de Jussieu, commenting on the numerical system of 

 Linnaeus. In the old systems, beginning with Tournefort, too 

 much weight may have been attached to the character of sym- 

 petaly. In the Bessey system the character of superior or in- 

 ferior ovary may have been given too much weight. Again in the 

 Hutchinson system the character of woody versus herbaceous 

 plants may have been over-emphasized. In the future the 

 natural classification of the higher plants will gradually develop 

 and it will include all characters. "The jewels in the crown of 

 phylogeny," says Zimmermann, "will only then become sig- 

 nificant, when all are together, their beauty many times en- 

 hanced by their mutual reflections." 



References 



Diels, L. Die Methoden der Phyteogeographie und der Systematik der 

 Pflanzen, pp. 143-145, in Abderhalden, Handbuch der biologischen Arbeits- 

 methoden. 1920. 



Hering, Martin. Die Oligophagie der blattminierenden Insekten in 

 ihrer Bedeutung fur die Klarung phytophyletischer Probleme. Jordan & 

 Horn's Verhandl. III. Internat. Ent.-Kongress. Zurich, 1925. 2: 216-230. 1926. 



Hutchinson, J. The Families of Flowering Plants, I. Dicotyledons, pp. 

 6-7. London, 1926. 



Sinnott, E. W. Investigations on the Phylogeny of the Angiosperms, I. 

 Amer. Jour. Bot. I, pp. 303-322. 1914. 



Sprague, T. A. The Classification of Dicotyledons, II. Evolutionary 

 Progressions. Journal of Botany LXIII, pp. 105-113. 1925. 



Wernham, H. F. Floral Evolution with particular Reference to the Sym- 

 petalous Dicotyledons. New Phytologist, 1913. 



Zimmermann, W. Die Phylogenie der Pflanzen, pp. 334-337. Jena, 1930. 



Brooklyn Botanic Garden 



