Xll PEOCEEDINGS OF THE 



asserted that it is the seed-integument, not the carpellary envelope, 

 that is deficient — a view which has been supported by Parlatore and 

 others, refuted by Hooker, Caspary, Eichler, and others, and again 

 taken up by Prof. Strasburger, of Jena, after a series of careful and 

 detailed organogenetic observations, combined with genealogical, or, 

 as they term it, phylogenetical considerations, in a remarkable essay 

 entitled 'Die Coniferen und die Gnetaceen.' In the attempt to re- 

 concile views apparently so opposite, taken by naturalists whom we 

 should all consider of high authority, we must, perhaps, in some 

 degree, take also into account a certain bias which may be obser- 

 vable on either side. Prom the well-known accuracy of Brown's 

 observations and the soundness of his views in every department of 

 botanical science he entered into, there is a great disposition on the 

 one side to rely absolutely on his conclusions ; whilst on the other 

 hand French orgauogenesists, having broached theories which have 

 proved of great importance in various homological questions, have 

 been but too ready to set them up against all authority, without 

 sufficient verification of detail. In the present case this verifica- 

 tion of detail has been suppUed by Strasburger, who has combined 

 it with general considerations now first brought to bear on the 

 gymnospermy of Conifers. He proves to be an ardent disciple of 

 Hackel, the greatest amongst Germauizers of Darwinism. The tes- 

 timony in favour of the derivative origin of forms and organs has 

 certainly received large accessions from the German accuracy and 

 copious details of Hackel and his followers, but at the same time 

 has been the occasion of a free display of German imagination, 

 as I hope presently to show, in considering Strasburger's views of 

 the homologies of Conifers, in conjunction with some parts of Hackel's 

 last great work, the Monograph of Calcisponges. 



In the first place, we must be careful to consider what we mean 

 by homologies of organs. They are of two kinds : — (1) the homo- 

 logy of the several appendages to the axis of one and the same plant, 

 which in zoology may be compared to the homology of the front and 

 hind limbs or of the several vertebrae of one and the same animal ; 

 and (2) the homology of the organs of two difierent plants, corre- 

 sponding to the homology, for instance, of the wing of a bird with 

 the fore leg of a quadruped. To the former class belong the various 

 much-vexed questions on the distinction between axis and appen- 

 dages, arising in the consideration of the flowers of Conifers as of 

 many other orders ; but it is the latter class with which we are now 

 more specially concerned in relation to Brown's gymnospermoiis 



