PERIOD III. 1729-1780 7 



put his name to it.'' Dillenius, who was quite aware of the prejudice against 

 aliens, himself writes also to Dr Richardson: "there being some apprehension 

 (me being a foreigner) of making natives uneasy if I should publicate it in 

 my name." Lichens were already engaging his attention, and descriptions 

 of 91 species were added to Ray's work. So well did this edition meet the 

 requirements of the age, that the Synopsis remained the text-book of 

 British Botany until the publication of Hudson's Flora Anglica in 1762. 



William Sherard died in 1728. He left his books and plates to the 

 University of Oxford with a sum of money to endow a Professorship 'of 

 Botany. In his will he had nominated Dr Dillenius for the post. The great 

 German botanist was accordingly appointed and became the first Sherardian 

 Professor of Botany, though he did not remove to Oxford till 1734. The 

 following years were devoted by him to the preparation of Historia Mus- 

 corum, which was finally published in 1741. It includes an account of the 

 then known liverworts, mosses and lichens. The latter — still considered by 

 Dillenius as belonging to mosses — were grouped under three genera, Usnea, 

 Coralloides and Lichenoides. The descriptions and figures are excellent, and 

 his notes on occasional lichen characteristics and on localities are full of 

 interest. His lichen herbarium, which still exists at Oxford, mounted with 

 the utmost care and neatness, has been critically examined by Nylander and 

 Crombie' and many of the species identified. 



Dillenius was ignorant of, or rejected, Micheli's method of classification, 

 adopting instead the form of the thallus as a guide to relationship. He also 

 differed from him in his views as to propagation, regarding the soredia as 

 the pollen of the lichen, and the apothecia as the seed-vessels, or even in 

 certain cases as young plants. 



Shortly after the publication of Dillenius' Historia, appeared Haller's^ 

 Systematic and Descriptive list of plants indigenous to Switzerland. The 

 lichens are described as without visible leaves or stamens but with "corpus- 

 cula" instead of flowers and leaves. He arranged his lichen species, 160 in 

 all, under seven different Orders: i. "Lichenes Corniculati and Pyxidati"; 

 2. "L. Coralloidei"; 3. "L. Fruticosi"; 4. "L. Pulmonarii"; 5. "L. Crustacei" 

 (with flower-shields); 6. "L. Scutellis" (with shields but with little or no 

 thallus); and 7. "L. Crustacei" (without shields). 



This period extends till near the end of the eighteenth century, and 

 thus includes within its scope the foundation of the binomial system of 

 naming plants established by Linnaeus'. The renowned Swedish botanist 

 rather scorned lichens as "rustici pauperrimi," happily translated by 

 Schneider^ as the "poor trash of vegetation," but he named and listed about 

 80 species. He divided his solitary genus Lichen into sections: i. "Leprosi 

 tuberculati"; 2. "Leprosi scutellati"; 3. "Imbricati"; 4. "Foliacei"; 



' Crombie 1880. ^ Haller 1742. ^ Linnaeus 1753. ^ Schneider 1897. 



