THE NUMBER OF PLANTS KNOWN TO SCIENCE. 



A comparison of the number of species of plants known to the 

 various learned men, who have lived during the past 2,000 years, and 

 whose names are more or less familiar to us, shows how marvelously 

 our knowledge of plants has been increased. Thus Hippocrates, 

 called the " Father of Medicine," who lived between 500-400 B. C, 

 knew only 234 species or kinds of plants. Theophrastus, 37 1-2 25 B. 

 C, who was perhaps the first real botanist whose name has been 

 handed down to us, described about 500 species of plants, which he 

 divided into trees, herbs and shrubs. By Dioscorides (77 A. D.) the 

 number was raised to 600 species, and by Pliny (23-79 A. D.) to 800 

 species. During the ensuing fifteen hundred years and more, com- 

 paratively little work was accomplished. Ray, who wrote between 

 1685 and 1704, enumerated and described 18,625 species of plants. 

 The number of plants known to Linnaeus in 1771 was only 8,551 

 species, less than half. the number supposed to have been known to 

 Ray. Persoon in 1807 recognized 20,000 species of flowering plants, 

 while DeCandolle in 1809 recognized 30,000 species. In 1824 Steudel 

 enumerated 70,000 species, including flowering and lower plants. This 

 number was raised by Lindley in 1845 to 79,837. In 1885 Duchartre 

 estimated the number of known plants of all groups at 125,000. 

 Durand in 1888 distributes the flowering plants as follows: Families, 

 210; genera, 8,417; species, 100,220; but as this enumeration was 

 based on the extremely conservative work of Bentham and Hooker, 

 the number was even then much larger. An estimate made about 

 five years ago placed the number of known plants in the world at 

 173,706, of which the seed plants made up about 125,000. Consider- 

 ing the number of new species published every year, it is probable 

 that the number now in the books is not much short of 200,000 

 species. — F. H. K. 



Dr. Coulter, of the University of Chicago, has just distributed 

 extras of his address as retiring president of the Botanical Society of 

 America. The subject is, " The Origin of Gymnosperms and the Seed 

 Habit," and in it Dr. Coulter presents quite cornpletely the latest in- 

 formation bearing on this interesting problem. He regards the gym- 

 nosperms as having come from the Cordaites, a great group of seed- 

 plants which flourished in Palaeozoic times, and which was probably 

 derived from certain early ferns, represented to-day by the Marattia 

 forms and their allies. The seed habit appears to have resulted from 

 the reduction of the megaspores (female spores) to one, and the reten- 

 tion of this in the megasporangium. 



