CHAP. 11. OVULE. 183 



" I have remarked the fifth envelope, or quintine, in many 

 species ; its general characters are such as to prevent its being 

 mistaken. Its complete development takes place only in a 

 nucleus which remains full of cellular tissue, or in a quartine 

 that has filled with the same. At the centre of the tissue is 

 organised, as in a womb, the first rudiment of the quintine ; 

 it is a sort of delicate intestine, which holds by one end to the 

 summit of the nucleus, and by the other end to the chalaza. 

 The quintine swells from top to bottom ; it forces back on all 

 sides the tissue that surrounds it, and it often even invades the 

 place occupied by the quartine or the nucleus. A very 

 delicate thread, the suspensor, descends from the summit of 

 the ovule into the quintine, and bears at its extremity a 

 globule which is the nascent embryo." 



It is apparently this quintine that Brown describes, in 

 the ovule of the Orchis tribe, as a thread consisting of a 

 simple series of short cells, the lowermost joint or cell of 

 which is probably the original state of what afterwards, from 

 enlargement and deposit of granular matter, becomes the 

 opaque speck, or rudiment of the future embryo. {Observ. 

 on the Organs^ Sfc. of Orcli. and Asclepiad. pp. 18, 19.) 



*' The existence," continues Mirbel, " of a cavity in the 

 quartine, or, indeed, the destruction of the internal tissue of 

 the nucleus, at the period when the quintine developes, 

 becomes the cause of some modifications in the manner of 

 existence of this latter integument. The quintine is never 

 seen, in certain Cucurbitaceae, adhering to the chalaza : it is 

 nevertheless evident that the adhesion has existed. The 

 quintine, distended at its upper part, and suspended like a 

 lustre from the top of the cavity, still presents at its lower end 

 a portion of a rudimentary intestine become distinct ; the 

 separation occurred very early, in consequence of the tearing 

 of the tissue of the nucleus. 



" Tlie quintine of Statice is reduced to a sort of cellular 

 placenta, to the lower surface of which the embryo is attached. 

 This abortion of the quintine arises from the quartine having 

 a large internal cavity, which prevents the young quintine 

 from placing itself in communication with the chalaza, and 



N 4 



