Amphit arpcea monoica. 307 



reaction. No starch is found in the section, nor have tannin 

 canals been located. 



During the life of this plant some marked physiological 

 changes seem to occur, the character of which is not yet 

 understood. Nor can it yet be stated whether there is any 

 connection between fruit production and the progress of the 

 changes or not. Further investigation may elucidate the 

 meaning of what has been observed. 



General Appearance of Leaves. 



As has already been stated, the first green leaves of 

 Amphicarpcsa are simple and opposite. They are netted- 

 veined, broadly ovate, with rounded apex, hairy upon both 

 surfaces, and also upon the margin, which is entire ; the 

 stipules are interpetiolar. At the base of the petiole, and 

 also at the base of the blade is a pulvinus. The petiole is 

 about one and a half times the length of the blade, and 

 both it and the pulvini are retrorsely hairy. The remain- 

 ing leaves are compound, provided with stipules, and are 

 arranged alternately. They are pinnately trifoliate, petio- 

 late and stipellate. The primary pulvinus is usually very 

 well developed, being at least four times the size of those 

 belonging to the leaflets. The terminal leaflet possesses a 

 petiole of its own — a continuation of the main one, also a 

 pulvinus and two stipels. The petiole of this leaflet makes, 

 with that of the main leaf, an obtuse angle ; thus its blade 

 lies in the same plane as the remaining leaflets. Each 

 lateral leaflet is attached by a pulvinus only, and is pro- 

 vided with a single stipel. All leaflets are ovate, with an 

 acute apex, the blade being longer than those of the simple 

 leaves ; but the terminal is larger than its fellows. The 

 lateral leaflets are rarely symmetrical, the outer side being 

 much wider. In other characteristics the compound resem- 

 ble the simple leaves. All leaves are remarkably thin, and 

 of delicate texture. The petiole forms with the stem an 



