120 



BIOCHEMICAL SYSTEMATICS 



Despite the preceding statement, there are no cases known to 

 the writers in which data concerning the fat composition of species 

 were appHed to the solution of a taxonomic, or more specifically, 

 a phylogenetic, problem. There are not even any contributions which 

 attempt to infer relationships from such data, in contrast to, for 

 example, Hegnauer's treatment of the isoquinoline alkaloids (Chapter 

 9). It is apparent that Hilditch was not necessarily implying that a 

 natural system of classification could be constructed out of the distri- 

 bution of seed fats. This may be ascertained from inspection of 

 Table 7-1. For example, in Group A, whose major component acids are 

 linoleic, linolenic, and oleic, families in the gymnosperm order 

 Coniferae and the angiosperm families Juglandaceae, Labiatae, and 

 Oenotheraceae among others are included; in Group D, whose major 

 component acids are palmitic, oleic and linoleic, families such as 

 Gramineae, Magnoliaceae, Solanaceae, and others are included; and in 

 Group K, whose major components are stearic, palmitic, and oleic 



Table 7-1. Distribution by family of some fatty acids (Meara, 1958). 



