356 Mr. A. Henfrey on the Vegetable Ovule. 



rngiceps ; but there can be no doubt, from the figure and descrip- 

 tion, that it is the Uperodon ornatum of Mr. Bell, which is figured 

 in the Zoologj^ of the Beagle, p. 50. t. 20. f. 6. 



Dr. Hallowell, in a paper in the same volume, describes and 

 figures some Snakes as new, which Dr. Gunther informs me are 

 well-known species, described many years ago, thus : — 



Zamenis tricolor, Halloiv. =: Herpetodrjas margaritiferus, Schleg. 

 Elapoidis fasciatus. Hallow. =: Streptophorus Sebsc, Dum. df Bibr. 



XXXIII. — On the Relation of the Raphe to the Coats of the Vege- 

 table Ovule. By Arthur Henfrey, F.R.S. &c. 



In the last number of the 'Annals' appeared a paper by Mr. ]\Iiers 

 explanatory of his views on the subject named in the heading of 

 this note. A clear statement of opinion is most valuable for the 

 settlement of debated questions ; and the setting-out therein of 

 the premises on which all the reasoning depends, is just what is 

 required for the decision of the value of the arguments in the 

 present case. 



These premises appear to us open to adverse criticism, taking 

 away the principal grounds of the subsequent arguments. We 

 will consider them seriatim, as laid down at pages 276-8. 



1. That "vegetable growth in all its stages is regulated by 

 the ordinary laws of mechanical action,'' is incorrect if taken 

 without qualification, since all the peculiar phgenomena of organic 

 development are indications of the action of a special force mo- 

 difying the eff'ects of simple mechanical laws ; but this question 

 has no important bearing in the present case. 



2. It is by no means true that every tunic of an ovule is 

 formed of three elementary parts, epiderm, mesoderm, and endo- 

 derm. No such distinction of parts occurs in the ovules of 

 Orchis and many other plants, where the ovules are composed of 

 comparatively small quantities of cells. 



3. Communication of vessels can only take place between one 

 tunic and another at points where they are organically continuous. 



4. The organic communication of the first and second tunics, 

 testa, and tegmen, is usually confined to the vicinity of the 

 chalaza or gangylode. 



5. In erect ovules the chalaza is, of course, contiguous to 

 the hilum. 



6. In anatropous ovules the chalaza is removed from the vici- 

 nity of the hilum ; but the inversion of the ovule takes place by a 

 one-sided development of the tunics of the ovule, — of the single 

 coat where only one exists, of the outer coat where two exist ; and 

 the cord of vessels lying in what is called the raphe is organically 



