STRUCTURE.] MORPHOLOGY OF IRREGULAR FLOWERS. 77 



7. The ovules of the Papilionacese are hemitropous. 



8. The embryo originates from the pollen tube at the 

 micropyle end of the embryonal sac, and increases either 

 from this place towards the chalaza, or (being propelled by 

 the pollen tube, which has become cellular, to the centre of 

 the embryonal sac), both in the direction of the chalaza and 

 that of the micropyle. 



9. The epidermis of the seed is formed in the Leguminosse 

 only of one integument, which, however, always separates 

 into several layers. 



10. No endopleura tumida exists in the Leguminosse ; 

 what has been considered as such is albumen, and, in fact, 

 endosperm. 



The authors have also discovered that the ovules of the 

 genus Lupinus are only provided with a simple integument, 

 while those of the other Leguminosse always possess a double 

 one. (Annals of Natural History, vol. iii.) 



C. Progressive development of Irregular Flowers, by M. Bar- 

 neoud. If a flower of Orchis galeata be examined in the 

 very earliest condition, it will be found to consist of a simple 

 cupula of very transparent tissue, on the border of which 

 three round equal teeth soon become visible ; these constitute 

 the exterior verticil, which is formed exactly in the same 

 manner as a true monophyllous calyx. In a short time a 

 second cupula is seen to originate in the interior of the first, 

 and its substance quickly becomes blended with that of the 

 latter, except that its border exhibits three small prominences, 

 perfectly equal and alternating with the teeth of the exterior 

 verticil. Thus the author considers that organogeny clearly 

 demonstrates in the Orchidacese, as in most other monocoty- 

 ledonous families, analogies of the calyx and corolla of 

 dicotyledons. The three nascent segments of the interior 

 verticil of Orchis galeata are quite similar in the early 

 condition, and it is not until a subsequent period that one 

 becomes evidently broader and more fully developed than the 

 two others ; this it is which becomes the labellum. Orchis 

 Morio, Ophrys araneifera, and two exotic genera, a Maxillaria 

 and an Oncidium, presented exactly identical conditions. 



