Vesicles of the Utricularia3. 391 



by Scbacht as foliaceous brauclilets, which, when young, are 

 rolled in, like a crozier, towards their apex, like the fronds of 

 ferns ; below this apex new leaves are successively formed, at 

 the axils of which a little conical body is soon seen to make its 

 appearance, composed of small cells, like the commencement of 

 a bud. This little body soon presents, towards its rounded ex- 

 tremity, a small excavation produced by an arrest of development 

 of the cells of the apex ; the edge thus formed rises more and 

 more, and the little cellular body, which was at Urst sessile, 

 soon afterwards shows at its base a prolongation in the form of 

 a pedicel. 



The side walls of the young utricle become more and more 

 developed, the aeriferous cavity which they enclose becomes 

 constantly larger, the edges of the side walls become inclined 

 towards each other and fold inwards, and the cavity, which was 

 originally open, is closed. The old aperture, indeed, presents a 

 valve formed by a fold of the margin of the opening. The 

 beard which, according to Schleiden, closes this aperture is 

 formed subsequently, upon its outer surface. 



After this description of the formation of the utricles, accom- 

 panied by the beautiful figures to which one is accustomed in 

 Schacht's works, this author mentions the changes of colour 

 which are observed in these organs — a fact previously observed 

 by Goppert. He likewise describes the singular hairs which 

 occur on the inner utricular surface. These hairs consist of five 

 cells, of which one forms the base, two spread out almost hori- 

 zontally, whilst the other two project into the interior of the 

 utricle. The basal cell of these hairs, as well as those which it 

 supports, results from the division of a small cell, which, in the 

 youth of the utricle, makes its appearance like a little stopper 

 in the intercellular canals. 



From what precedes, Schacht concludes that the utricles of 

 Utricidaria are a modification of the ramifications of the axis, 

 and not of the leaves. 



In the month of April 1867, I investigated the formation of 

 the utricles in Utricularia minor collected in the marshes of 

 Jogny above Vevey. Schacht, who studied the formation of the 

 utricles in Utricidaria vul(/aris, assumes as the rule their forma- 

 tion in the axilke of the leaves, and deduces therefrom their 

 analogy with buds. We see, in fact, little bodies composed of 

 cells make their appearance between the ramifications of the 

 leaves; these present a conical form, with their free extremity 

 slightly rounded. These little bodies, which are at first com- 

 pletely sessile, are soon raised upon a small pedicel, the cells of 

 \Ahich are afterwards differentiated into an outer layer corre- 

 sponding to the layer of pareucbvm.a which follows the veins of 



