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To the Experimental section belong the collections of 

 plants growing in cold conservatories and of plants 

 growing in the open air, all of which are specially dispo- 

 sed for providing instruction. 



These plants are arranged in five groups. 



i Systematic Botany. This collection is classified 

 according to Engler's system. All the vegetable groups, 

 from the Schizophytes, the Mushrooms and the Algae to 

 the Phanerogams, are represented; they are placed in one 

 single series, including also the aquatic plants, the plants 

 growing in the shade, trees, etc. 



2 Etiology. In this class, the specimens are arranged 

 according to their adaptations to the medium in which 

 they are living : a) vegetative adaptations for the 

 preservation of the individual; b) adaptations for repro- 

 duction and dissemination having as object the preser- 

 vation of the species. 



To show the adaptations frequently peculiar to equato- 

 rial plants, hot houses are provided, one for vegetative 

 adaptions, another for reproduction and dissemination, 

 while a third is reserved for the aquatic plants and 

 creepers. 



3 Phytogeny. These collections are arranged in the 

 best way to show the different kinds of variations 

 (streaks, double flowers, etc) and hereditary characteristics 

 (hybridisation, difference in characteristics, etc.); they 

 also show 7 the different varieties of cabbages, pan- 

 sies, etc. 



4 Geo-botanics. Hitherto these collections consist 

 only of plants growing in cold conservatories. 



5 Horticulture : the ornamental plants are disseminated 

 throughout the whole garden. 



IV. SECTION OF CRYPTOGAMS AND VEGETABLE PATHOLOGY 



This section includes the herbarium (90,000 sheets) the 

 cryptogamic material in the garden and specimens for the 

 study of Phyto - pathology . Numerous specimens of 

 diseased plants and of parasites are sent to the garden. 



