Mr. J. Miers on the Menispermacese. 15 



anomalous departure from the above-mentioned otherwise uni- 

 versal rule. Here, although the radicular end of the embryo 

 ]'emains in its normal position, its cotyledonary extremity is not 

 directed as usual to the point of attachment of the fruit, but it 

 wanders to some uncertain station through a helical channel. 

 The putamen contains a single orbicular seed, which is greatly 

 flattened and covered by a thin membranaceous integument ; 

 from a point on its periphery, just below the persistent style, 

 and close to the basal attachment of the putamen, the cell be- 

 gins to be intercepted by a thin partition, which curves spirally 

 until it terminates in the exact centre of the seed, thus com- 

 pleting in its course two and a half gyrations, and the embryo 

 is found within the spiral cell of the integument, without any 

 albumen. This spiral division is, in fact, the condyle, which at 

 its commencement is like that seen in Tiliacora, Diploclisia, &c. 

 — where, terminating a little beyond the middle of the cell, it 

 divides it into a bimarsupial or hippocrepiform pouch ; but in 

 Spirospermum this septiform condyle is continued far beyond 

 that point, in an extremely attenuated state, under the form of 

 a spiral coil, which reaches the centre in the manner before de- 

 scribed. This septiform line is attached to the two opposite 

 inner faces of the putamen, as in the other genera ; and when a 

 knife is passed round the periphery of the putamen, its two 

 flattened sides are easily torn away from the adherent edges of 

 the condyle, leaving a corresponding helical cicatrix upon the 

 tv»'o faces, and showing correlative groove-s on the outer surfaces 

 of the putamen. We might suppose that the embryo would till 

 the entire length of the helical cavity of the integument ; but it 

 was otherwise in the specimens I examined ; for although this 

 spiral cavity consisted of nearly three gyrations, the elongated 

 slender einbryo only extended through half of the first turn, 

 the remaining two gyrations being quite empty ; the radicular 

 end, however, touched its normal point on the periphery, at the 

 beginning of the first coil. 



I have explained how the development in Tiliacora, Diplo- 

 clisia, 8zc. takes ])lace by the simple process of excentric growth; 

 indeed in all the genera of the family, even in the more extreme 

 cases just mentioned, the amount of curvature of the integu- 

 ment and seed is coequal and symmetrical with the unequal 

 expansion of the ovary, and therefore of the pericarp and puta- 

 men ; but in Spirospermum the one greatly exceeds the ratio of 

 the other, as is shown above ; and this forms a solitary exception 

 to the otherwise general rule. 



It would be instructive if we could ascertain the cause of this 

 singular growth. In all cases the original ovular integument 

 grows lengthways ; and in Spirospermum wc might suppose that 



