Feb. 180;].] BOTANICAL SOCIETY OF EDINRURGH. 577 



or two leaves, and a long, narrow, linear leaf is left which 

 gradually narrows until no expansion at all remains and 

 the leaf is represented by its midrib alone, terminating in a 

 hard sharp spine when the adult spine leaf form is reached. 



Variations from this type are of very frequent occurrence, 

 and of these, perhaps, the most common is the entire 

 absence of the simple leaves intercalated between the coty- 

 ledons and the tripartite leaves, these last following in this 

 case directly on the cotyledons without the appearance of 

 any transition forms. About fifty per cent, of the seed- 

 lings which I have examined show no trace of simple leaves 

 between the cotyledons and the trifoliate leaves, but in 

 other respects closely resemble the type, while the remain- 

 ing fifty per cent, are typical. 



A form, however, in which all the leaves appear to be 

 spathulate is mentioned by Sir John Lubbock (v., p. 410). 

 The same author describes another seedling in which the 

 first two are " linear-oblong," the second pair are provided 

 with one lateral leaflet each, the fifth leaf is spathulate, the 

 sixth " trifoliolate," and the eighth and ninth each provided 

 with a lateral leaflet, while the succeeding leaves are 

 spathulate. In both these cases there has clearly been an 

 increase in the number of the spathulate simple leaves at 

 the expense of the trifoliolate form, but in both simple 

 leaves follow directly on cotyledons. 



In another plant described by the same author, the first 

 six leaves were trifoliolate, the remainder up to the eleventh 

 being simple, while in other two specimens described by 

 him other modes of arrangement of the three kinds of 

 leaves occur, such as the intercalation of a spathulate leaf 

 between two bifoliate leaves, or between the zone of tripar- 

 tite leaves following directly on the cotyledons and the 

 succeeding bipartite leaves. 



Hildebrand (iv.), while describing and figuring the 

 successive leaf-forms of what I regard as the typical case, 

 mentions that in some seedlings the first simple leaves are 

 altogether omitted, the tripartite leaves following directly 

 on the cotyledons. Winkler (vi.), on the other hand, 

 inclines to the view that this occurs in the majority of 

 cases, and is in fact typical, he having only observed one 

 specimen in which the tripartite leaves were preceded by 



