96 MR. К. P. GREGORY ОХ THE 
other hand, in some cases the size of the ovary may be made use of. Thus in 
figs. 19 and 20 two sister plants are illustrated, the one long-styled, the other 
short-styled. In the former, the ovary of the central flower of the суте in 
several cases reached, after the corolla had dropped, a length of 3 mm., and 
in one case was 2*6 mm. long (fig. 22) ; while the ovaries of the corresponding 
flowers in the latter plant were never more than 1 mm. long. 
The male plants may be fairly readily divided, on inspection, into two 
classes, according as the style is visible from above, without dissection of the 
flower, or not. But this line of separation is a very rough one, since the 
degree of visibility of the style depends upon many other factors than its 
length, and is largely affected by such characters as the openness of the 
throat of the corolla, and the development of the hairs in the throat. More- 
over, even in plants in which the style ultimately reaches some length, in the 
younger stages it is much shorter and often quite invisible from above. For 
these reasons such a line of separation would include, with the short-styled 
plants, many which, if the classes are to be retained at all, ought to be placed 
among the long-styled forms. 
Atan early stage of this investigation it became apparent that, under each of 
the two classes “ long-styled " and * short-styled,” more than one type of flower 
would have to be included. For convenience of recording, five forms were 
therefore chosen as types, and each plant was entered according to the type 
which it most nearly resembled. ОГ the five types А, В, C, D, and E (see 
figs. 32, 34-37 and explanation of Plate), А and В are long-styled, D and Е 
are short-styled, and C is intermediate between the two. The lengths of the 
styles in the flowers referred to the different groups were approximately :-— 
Group À : 2 mm. and over. Group С: 1°1-1°б mm. 
Group В: 1°4—1'9 mm. Group D : 0:6-I:0 mm. 
Group E : 0:5 mm. and under. 
But a really nearer idea of the types may be given by saying that :— 
In Group A, the style reaches nearly or quite to the top of the corolla- 
tube. 
In Group В, the style 13 somewhat shorter, but reaches а point above 
the level at which the stamens are inserted on the corolla-tube. 
In Group C, the style barely reaches the level of the insertion of the 
stamens. 
In Group D, the style does not reach the level of the insertion of the 
stamens. 
In Group E, the style 1з a very small rudiment. 
Plants belonging to group X are easily recognizable, the style standing up 
prominently in the middle of the corolla-tube in the mature flowers (figs. 21, 
33, 25). Plants belonging to the other groups are by no means so easily 
