140 Development of the Natural System under [Book i. 



appreciated during that time in Germany than in any other 

 country. Robert Brown, who spent the five years from 1801 

 to 1805 in Australia, studied the flora of that quarter of the 

 world, and discussed in numerous essays the botanical results 

 of various journeys made by other naturalists in polar regions 

 and in the tropics. In this way he found opportunity to leaven 

 the ideas, which through Humboldt's influence had become 

 predominant respecting the geography of plants, with the spirit 

 of the natural system ; he also made the morphology and 

 systematic position of a number of families the subject of 

 critical investigation. 



Robert Brown's literary efforts were limited to these mono- 

 graphs ; he nowhere attempted to give a connected account of 

 the principles which he follows in them, an exposition of his 

 morphology or a theory of classification, nor did he frame a new 

 system. The results of his studies which were really fruitful 

 and served to advance the science are to be found in the more 

 general remarks, which he managed to insert quite incidentally 

 in his monographs. In this way he succeeded in clearing up 

 the morphology of the flower and with it the systematic position 

 of some difficult families of plants, such as the Grasses, Orchids, 

 Asclepiads, the newly-discovered Rafflesiaceae and others, and to 

 throw new light at the same time on wider portions of the system ; 

 in his considerations on the structure and affinities of the most 

 remarkable plants, which had been collected in Africa by 

 different travellers in the years immediately following 1820, he 

 discussed difficult and remarkable morphological relations in 

 the structure of the flower. He referred especially in this essay 

 (1826) to the relations between the numbers of the stamens and 

 carpels, and those of the floral envelopes in the Monocotyledons 

 and Dicotyledons, and showed how these typical, or as he calls 

 them in De Candolle's phraseology, symmetrical relations were 

 changed by abortion, while he entered at the same time into a 

 more exact determination of the position of the aborted and of 

 the perfect organs, in order to discover new relations of affinity. 



