THE LICHEE LirE-CXCLE 221 



>ns may be outlined, expressing the varied fortunes of many 

 es of the sea in the intensified struggle for existence during 



cerrelatioi 



algal races of the sea in the intensified struggle tor existence during 

 the vicissitudes of such a change of phase. There is little question 

 of tracing fanciful lines of phyletic descent, 1 but it should be possible 

 to reconstruct the biology of the phases of the progression in the 

 response of divergent organism of similar horizons to the changing 

 conditions of their environment. In recasting the history of such 

 ancient epochs, no point or detail is too small to be without some 

 bearing on the case ; even the works of previous writers may be 

 re-examined for more vivid interpretations, and one begins to take a 

 renewed interest even in the commonest types when they are viewed 

 from a new angle. There can be no doubt that in the organization 

 of these curious survivals there may be traced the history of many 

 lost races, which may afford confirmatory evidence of the determining 

 factors of plant- progression, its aims and ultimate significance in the 

 world-scheme. 



JAMES YATES'S DRAWINGS OF CYCADS. 

 By James Britten, F.L.S. 



It is somewhat remarkable that in the account of James Yates 

 (1789-1871) in the Dictionary of National Biography (lxiii, 297), 

 which deals at length with him as " unitarian and antiquary," no 

 reference is made to his botanical work in connection with the 

 ("i/cadacece. Both his collection of these at Lauderdale House, 

 Highgate (now included in Waterlow Park), to which he retired in 

 1848 and where the rest of his life was spent, is described by Seemann 

 (Bot. Herald, 201) as "the most extensive ever brought together in 

 anv garden, public or private " ; his specimens and drawings — the 

 former described in the Keport for 1806 as "a large and highly 

 interesting collection of specimens, consisting of sections of stems, 

 fronds, male and female cones in various stages of growth, separate 

 parts of fructification, etc." — are in the National Herbarium. The 

 specimens were presented by him in the year mentioned : the drawings 

 were at his death given by his widow to the Linnean Society (of 

 which Y"ates became a Fellow in 1822). by which body they were 

 transferred to the Department of Botany in 1914. It is of these 

 latter that I propose to give some account. 



1. Ci/cas circinalis. "Male cone of a Cycas (perhaps spheerica) 

 produced in the Bot. Garden, Copenhagen, and sent a.d. 1849 to the 

 Horticultural Society, London." " P. lustyne delt.," 1849, elephant 

 folio. 



1 Academic schemes of phyletic progression from incipient squamulae to 

 crustaceous and foliaceous forms, postulating- stray mycelium of unknown 

 origin, are more reminiscent of the vague ideas of spores scattered on the 

 primal naked surface of the earth, apparently as special creations (Lauder 

 Lindsay. British Lichens, 1856, p. 80), than of modern scientific demands for 

 some reason for such happenings, and some deeper conception of origins. The 

 point still remains to account for the Alga and the Fungus being there, and the 

 mechanism of their antecedent evolution (rf. A. Lorrain Smith. Lichens. ][)'2l). 



