90 PLANT MORPHOLOGY 



as incorrect, even before the evidence was adduced by an American 

 botanist (Frye) that Casuarina has evidently nothing which marks 

 it off from other angiosperms. Many of my fellow botanists have 

 been inclined to point out as a further example of the fruitlessness 

 of the search for primitive forms those bryophytes which have been 

 regarded by me as primitive; and I readily ' admit that here also 

 we cannot point out any conclusive evidence for their primitive posi- 

 tion, but only for a greater or less subjective probability. Numerous 

 other examples (as, e. g., the supposed primitive monocotyledons) 

 may be pointed out, which show that the phylogenetic morphology 

 has overrated the prospects of results in search for primitive forms, 

 stimulating as this has been. 



This may be seen also if we notice the attitude of phylogenetic 

 morphology to the problem which the old morphology dubbed 

 with the not very fortunately chosen name of metamorphosis, and 

 which historically is that of homologies. Here, also, it may be 

 shown that the problems have remained the same, while only the 

 attempts to reach a solution have changed. 



The idealistic morphology believes that all organs of the higher 

 plants may be traced back to caulome, phyllome, and trie home; 

 it conceived this process not as a real one, but was content with a 

 conceptual arrangement of different plant organs in these categories, 

 which were really nothing but abstractions. 



That thereby the reproductive organs were left entirely out of 

 consideration these were referred to modifications of vegetative 

 organs is explained in part by the fact that they occur in the higher 

 plants less frequently as peculiar parts, and often completely dis- 

 appear in teratological growths, which are with predilection turned 

 to account in theoretical considerations; and in part because of the 

 view that for morphology the function of an organ is a matter of 

 indifference, and that accordingly in morphological considerations 

 it can have no significance whether an organ has developed as a 

 glandular hair, chaffy scale, or as an archegonium, so long as it has 

 developed out of the outer cell-layer of the plant body! This stand- 

 point, which is an obviously sterile one, needs no further special dis- 

 cussion. Let us, on the other hand, see how phylogenetic morphology 

 has come to terms with the problem of metamorphosis. As an ex- 

 ample, I select a passage from a prominent American work, in which 

 Coulter and Chamberlain express themselves concerning the leaf 

 structures of flowers as follows: 



" While sepals and petals may be regarded as often leaves more or 

 less modified to serve as floral envelopes, and are not so different 



Embri/o-sac of Casuarina stricta, Bot. Gaz. xxxvi, p. 104) shows that the embryo- 

 sac of Casuarina stricta behaves just as in the other Dicoti/lcdonoe. Of this paper, 

 however, Engler has taken no notice. The whole of Engler's presentation shows 

 how far the desire to find primitive forms may lead to untenable views. 



