of Papaveraceae, and on the Stigma of Cruciferae. 251 



with parietal placentas ; and that it is therefore the reverse of 

 that exhibited by the more complex capsules. 



In Macleaya cordata the two parietal placentas bear several 

 ovules ; and the lobes of the stigma, though capable of sepa- 

 ration, are vertical and in close apposition, forming a furrowed 

 stigmatic line, which necessarily corresponds to the placentas, 

 and consequently alternates with the valves. 



In Chelidonium the stigmatic lobes (which in Macleaya were 

 capable of separation and complete reflexion) are more rigidly 

 erect, but the furrowed line bears the same relation to the pla- 

 centas, which now exhibit their bi-carpellary origin by bearing 

 a double row of ovules. 



In Glaucium the stigmatic lobes become enlarged, but other- 

 wise remain as in the last example. The parietal placentas are 

 furnished with a linear spongy growth projecting from be- 

 tween the rows of ovules of each placenta, and uniting with 

 that of the opposite side in the centre of the capsule, which ia 

 thus converted into two cells. This spongy dissepiment is 

 usually described as arising from the extension of the pla- 

 centas ; an attentive examination at different periods of growth, 

 however, will show that it is really distinct in structure, though 

 attached to them. 



In Hunnemannia we have the first indication of an addition 

 of parts ; the stigma being obscurely four-lobed, indicating 

 the manner in which new carpels will, in other genera, be- 

 come interposed between the two primary ones, which alone 

 exist in the preceding instances. 



In Eschscholtzia the additional stigmas (which are only in- 

 dicated in Hunnemannia) are considerably developed, but are 

 separate from the primary ones. The fact of their being the 

 superadded stigmas is however indicated by their being shorter 

 than the others. 



[In consequence of the separation of the stigmas in this ge- 

 nus, the primary or longer ones bear the normal relation to 

 the placentas, i. e. alternate with them, as already described in 

 Bocconia ; and the superadded stigmas (the shorter ones), 

 which are opposite to the placentas, are so only in consequence 

 of the non-development of the carpels to which they really be- 

 long. It will be perceived, that whilst in this genus the ap- 

 proach towards a greater complexity of structure takes place 

 in some organs, others appear to have retrograded towards 

 the normal state as it is exhibited in Bocconia, the first in- 

 stance in the series ; thus, the increased development of the 

 superadded stigmas which necessitates the placing of the ge- 

 nus after Hunnemannia, and consequently after Glaucium and 

 Chelidonium, is attended by the separation of all the stigmas, 

 and the consequent alternation of the primary ones with the 



