n8 Development of the Natural System under [BOOKI. 



many important points of view, from which they could after- 

 wards be discovered, and it certainly became the foundation 

 for all further advance in the natural method of classification ; 

 for this reason it is necessary to give a view of it in the follow- 

 ing table :- 



A. L. de Jussieu's System of 1789. 



CLASS. 

 I. 



III. 



o 



Acotyledones . ........ 



Stamina hypogyna ..... II. 



Monocotyledones perigyna . 



epigyna ..... IV. 



l Stamina epigyna ..... V. 



Apetalae perigyna . . VI. 



( hypogyna ..... VII. 



/Corolla hypogyna .... VIII. 



L , 1 perigyna ..... IX. 



Monopetalae < ^ v 



} . \ anthens connatis . X. 



\ epigyna < . 



* ( distinctis . XI. 

 p 



! Stamina epigyna . . . XII. 



hypogyna . . XIII. 



perigyna ..... XIV. 



Diclines irregulares ....... X\ . 



i o 



This table shows that Jussieu did not oppose the Crypto- 

 gams, which he calls Acotyledones, to the whole body of 

 Phanerogams, as Ray did under the name of Imperfectae ; he 

 rather regards the Acotyledones as a class co-ordinate with 

 the Monocotyledones and Dicotyledones ; but this mistake or 

 similar mistaken views run through all systematic botany up to 

 1840 ; the morphology founded by Nageli and by Hofmeister's 

 embryological investigations first showed that the Cryptogams 

 separate into several divisions, which co-ordinate with the 

 Monocotyledons and Dicotyledons. At the same time the use 

 of the word Acotyledones for Linnaeus' Cryptogams shows that 

 Jussieu overrated the systematic value of the cotyledons, 

 because, as is seen from the introduction to his ' Genera 

 Plantarum,' he was quite in the dark on the subject of the great 

 difference between the spores of Cryptogamic plants and the 

 seeds of Phanerogams. His conception of the organs of 



