FLOWER OF PINGUICULA VULGARIS, ETC. 651 



P. caudata (Plate XXX. figs. 43-44). 

 Since bringing this paper before the Society, I have succeeded in extracting 

 an embryo, almost entire, from one of a very few seeds of this Mexican species 

 obtained from the University Herbarium in Dublin ; and I find that there are 

 two cotyledons, whose length is about one-half of that of the embryo, which 

 measures about ^jth of an inch. The embryo here, like the seed containing it, is 

 very narrow and considerably elongated. I have given two views of this speci- 

 men, so as to show the division between the cotyledons on either side ; from 

 which the fact that there are two cotyledons is abundantly manifest. In the 

 specimen figured, one cotyledon is a little shorter than the other ; this, however, 

 is accidental, as the cotyledons were of equal length in another embryo which I 

 extracted in a somewhat mutilated condition. 



Utricularia minor, L. (Plate XXX. fig. 45.) 



The embryo here is somewhat globular, about -^th of an inch in diameter, 

 and at first sight appears to have a smooth undivided surface ; on careful inspec- 

 tion, however, a remarkable conformation is to be observed of that end of the 

 embryo which is remote from the hilum of the seed, viz., a minute, slightly 

 convex punctum vegetationis surrounded by four slight elevations placed so as to 

 form the somewhat incurved sides of a square. I am not exactly prepared to 

 call these elevations cotyledons ; but the whole structure is interesting, as show- 

 ing this embryo to be a little in advance of a mere " embryonal globule," as are 

 most of the embryos described as " undivided" or " acotyledonous." 



Explanation of Plates XXVIII., XXIX., XXX. 



Plate XXVIII. 



Pinguicula vulgaris. 



Fig. 1. Extremity of winter-resting bud, showing rudiment of the inflorescence, and of the axillary 

 bud of the last leaf. I", 3d last leaf cut across; I', 2d last leaf; I, last leaf; ab, 

 axillary bud of last leaf; fl 1 , indication of 1st flower; fl 2 , that of 2d flower. Leaf- 

 spiral from right to left of observer supposed to occupy the axis. x 77. 



Fig. 2. Young inflorescence further advanced. The first flower (fl 1 ) distinctly projects, and 

 exhibits irregularity, being flattened from above anteriorly, downwards posteriorly, 

 although not even the calyx has appeared. Leaf-spiral from right to left. x 77. 



Fig. 3. Young inflorescence, in which the anterior sepals of the 1st flower are beginning to appear 



(sa). Leaf-spiral from left to right. x 77. 

 Fig. 4. Young inflorescence. Here the calyx of the 1st flower is now complete, and the corolla is 



visible, si. lateral sepal ; sp, posterior sepal. Leaf-spiral from right to left. x 77. 



Fig. 5. Young inflorescence. Fertile stamens (st) distinctly present, and staminodes (st') faintly 

 so in the 1st flower. pp } posterior, and pi, lateral petals. Leaf-spiral from left to 

 right. x 77. 



VOL. XXV. PART II. 8 G 



