276 Linnean Society. [Dec. 16, 



to become slightly prominent, and finally by a strain upon the vessels 

 of that particular part to fall off in the shape of a lid. In Couroupita 

 the pressure is sufficient to mark the surface of the fruit with a pro- 

 minence, but from th» partitions giving way early, and from the 

 abundant juices produced in the interior, there has not been, he con- 

 ceives, sufficient pressure to occasion disruption. In all the species 

 of Lecythis, he observes, the extent of the loose cover corresponds 

 with the extent of the axis, and what remains of the latter continues 

 attached to itf. 



As regards lomentaceous fruits in general, the author believes that 

 the intervals between the seeds being sufficient to admit of the sides 

 of the fruit cohering (which is promoted in particular instances by 

 special causes), the swelling of the seeds afterwards stretches the 

 parts over them in a degree which this coherence prevents from 

 being equally distributed, drags the tissue forcibly from the junc- 

 tures which are fixed points, and thus there being a strain in each 

 direction from the middle line of the juncture, the contraction of 

 drying during the ripening of the fruit effects the separation. 



Finally the author refers to the horizontal separations in the cap- 

 sules of Mosses, and observes that the separation of the calyptra 

 affords a plain example of the operation of his third principle ; Jbut 

 with regai'd to the nature of the operculum, although he has an hy- 

 pothesis under consideration, his mind is not yet satisfied. He states 

 his object in the present paper to have been the investigation of the 

 immediate physical causes of certain known effects, but he has not 

 thought this the place even to touch upon their ultimate causes or 

 the ends to accomplish which they are apparently designed, and 

 which adapt them to the position and general structure of the parti- 

 cular plant. 



Read also the conclusion of Dr. J. D. Hooker's " Enumeration of 

 the Plants of the Galapagos Islands, with descriptions of the new 

 species." 



In a brief introduction Dr. Hooker offers his acknowledgements to 

 Mr. Darwin, by whom the collection on which this enumeration is 

 chiefly founded was made, and to Prof. Henslow, in whose charge 

 the collection had been placed, and who kindly relinquished his in- 

 tention of publishing the novelties contained in it in favour of the 

 author. He also notices the striking peculiarities which mark the flora 

 of the Galapagos group, the plants composing which not only differ 

 in a great degree from those of any other country, but are in many 



