THE AEUM FAMILY. 167 



A comparative study should be made of such other 

 aroids as can be procured, e.g. sweet-flag, water-arum, etc. 

 Aside from the peculiarities of their inflorescence, which 

 mark them as a unique group, the acrid properties of many 

 members of this family constitute a marked feature.^ 



SPECIAL STUDIES. 



I. Morphology of the spathe. 



II. Comparison of arrangements for fertilization in 

 different genera of Araceae. ■* 



III. Active properties as a feature of relationship in 



this family. 



IV. Aflinities of the Aracese. 



1 Miiller, Fertilization of Flowers, pp. 562-565, should be consulted. 

 Some interesting facts and suggestions are given by Allen, Flowers and 

 their Pedigrees, pp. 236-266. Certain peculiarities of fruits and seeds 

 may be looked for as different genera are examined, such as — 



1. The gelatinous outer surface of the fruit of Peltandra. 



2. The seeds, — albuminous in some genera and exalbuminous in 

 others. 



3. The embryo, — ^ green in a number of genera. 



