50 Morphology BOOK i 



a fern. In the case of the Ascomycetes also, he identified 

 the fructification with what we now call the sporophyte. 



Sachs made much more clear than before the limitation 

 of the two phases in these Thallophytes by defining very 

 lucidly the term spore, which till the time he wrote had 

 been applied loosely to all asexual reproductive cells. He 

 says, ' For the purpose of a scientific nomenclature the 

 term Spore (if used in the same sense as in Muscineae and 

 Vascular Cryptogams) must be applied in Thallophytes only 

 to those reproductive cells which are the result of an act 

 of impregnation, whether direct, or indirect through the 

 production of a vegetative body which constitutes a second 

 generation and closes the entire course of development of 

 the plant. All other unicellular and non-sexual organs of 

 reproduction we shall not term spores, but gonidia or 

 conidia' He classed the latter with bulbils or gemmae. 

 He left, however, room for some confusion, as the zygote 

 or fertilized cell is a direct result of an act of impregna- 

 tion. His explanation of this inclusion is found in his 

 view that, ' if the act of fertilization did not result in the 

 production of any vegetative structure, or the second genera- 

 tion be altogether suppressed, the fertilized oosphere would 

 then itself become a spore, as in the Coleochaeteae, Oedo- 

 gonieae, and Vaucheria. In this case the spore is an 

 equivalent for the whole of the second generation, it stands 

 for the entire fructification of the Ascomycetes, the entire 

 spore-capsule of a Moss, &c.' 



Sachs' position was clearly that of Celakowsky, but he 

 carried his reasoning further, seeing an identity of pro- 

 cedure through the whole vegetable kingdom. Impressed 

 with this view he interpreted various appearances among 

 the Thallophytes somewhat arbitrarily, and saw homologies 

 the propriety of which are, at any rate, possible subjects of 

 discussion. He saw, however, more clearly than most of 

 his predecessors and carried the controversy much further. 



