Mr. J. Miers on the Ehretiaceai and Cordiacese. 383 



Fig. 8. Fusiform spicules, plain and warty, from ectodermic layer between 



base of tentacles and edge of hard tube. 

 Fig. 9. Warty fusiform spicules. 

 Fig. 10. The same, gradually becoming coalesced and forming a rough 



irregular network at one spot ; in another becoming solidified. 



N.B. All the figures on this Plate have been drawn by Mr. Ford from 

 specimens preserved in spirits. It need not be said that they are accurate 

 representations of the structures thus preserved ; yet they would un- 

 doubtedly have been much more life-like had they been drawn by Mr. 

 Ford from living specimens. Figure 3, however, is not only an accurate 

 but also to my mind a life-like drawing. 



XLVIII. — On the comparative Carpical Structure of the 

 Ehretiacese and Cordiacese. By John Miers, F.R.S., 

 F.L.S., &c. 



Thus far the carpical structure of the Ehretiacece has been 

 explained, especially under the typical form of Ehretia ; and 

 it will tend to a better comprehension of the subject if I offer 

 a few observations upon Cordia, because a very distinguished 

 botanist has proposed to amalgamate Ehretiacece with Cor- 

 diaceos. M. Baillon, in an instructive analysis of the ovary of 

 Cordia (Adans. iii. 1, pi. 1), points to the analogy existing in 

 the early development of the ovaries of Cordia and Heliotro- 

 pium, and, without sufficient consideration of the subject, he 

 pronounces these two genera to be inseparable ; and, as the 

 latter has been referred by some to Ehretiacece, he would unite 

 the Cordiem, Ehretiece, Heliotropiece, and Borraginece into one 

 family (Cordiacece). He thus divides it into two groups : — 



1. Borraginece proper. 



2. Cordiacece, subdivided into 



A. Corcliece, having an embryo with plicated cotyledons. 



B. Heliotropiece, with simple cotyledons, without albumen. 



C. Tournefortiece, with simple cotyledons, with albumen. 



But he does not state in which of these he would place the 

 Ehretiacece. 



These were the inferences he drew from his examination of 

 the ovary of Cordia ferruginea ; and he figured in the drawing 

 above quoted the different stages observed from the period of 

 the earliest development. He depicts the formation of two 

 rudimentary carpels, which, by the inflexion of their margins, 

 form a low dome with a unilocular cavity, in the bottom of 

 which, intermediate between the four cardinal points, he per- 

 ceived the evolution of four ovules, fixed in the base upon as 

 many placentary ridges, while between them four septiform 

 enlargements emanated from the wall of the cell at those car- 

 dinal points, leaving as many shallow fossets in the base 



