62 PLANT MORPHOLOGY 



ment is the foundation for all special botanical morphology." The 

 study of development thus introduced for the individual part was 

 soon extended to the whole life-cycle, and especially among the 

 lower forms, which had been so long neglected. The year 1848 should 

 be marked with a white stone in the chronology of every morpholo- 

 gist, for in that year the essential outline of the life-history of a fern 

 was completed by Suminsky. Hofmeister followed in quick succession 

 with the enunciation of the fundamental homologies in fern and 

 moss; and thus was laid, though upon a purely comparative basis, the 

 foundation of a scientific morphology for vascular plants. But the 

 comparisons were still formal, and might have been applied equally 

 well to dead as to living things. The inspiration of the breath of 

 life came with the theory of evolution: the facts then first "lived, 

 and stood upon their feet." It is, however, remarkable how slowly 

 the change of view brought by the theory of evolution permeated 

 morphology. Sound though Hofmeister's conclusions were on the 

 comparison of either generation as a whole, the same could not be 

 said of the comparison of the parts. It took almost a generation 

 after the publication of the Origin of Species for botanists to achieve 

 any practical appreciation of evolution as a factor in the morphology 

 of the appendages. The position up to 1874 is well reflected in the 

 text-book of Sachs. Though he himself points out the limitations 

 necessary to such a method, Sachs proceeds in the morphological 

 section of his book on the footing that in vascular cryptogams 

 and phanerogams "every organ is either a stem, or a leaf, or a root, 

 or hair." Sporangia are held to be the results of metamorphosis of 

 vegetative parts. The conception of homology which underlies 

 such a grouping is dictated rather by convenience of definition and 

 of classification than by any deeply lying aspiration after his- 

 torical truth. An important step towards placing the morphology 

 of the appendages upon a sounder footing was taken by Goebel in 

 1881, when he asserted the independence of the sporangium, as an 

 organ sui generis, and not a result of metamorphosis of any vegeta- 

 tive part. This was upheld by Sachs in the following year, in his 

 Vorlesungen. 



Another feature, and perhaps the most important, of the Vor- 

 lesungen, was that in them Sachs for the first time gave due weight 

 to the physiological aspect of morphology, and thus harmonized 

 those two branches of study which had too long been kept asunder. 

 The increasing attention thus given to physiology, and to the effects 

 of external influences, has naturally led to the initiation of a third 

 phase in the history of morphology: I mean the phase of experiment, 

 with a view to ascertaining the effect of external agencies in deter- 

 mining form: that phase is still nascent, and carries with it high 

 possibilities. But it is well in the enthusiasm of the moment to keep 



