828 



BIONOGRAPH OF THE BRITISH SPECIES OF EUPHRASIA. 



different climatic conditions, blotted out these more sharply bounded 

 areas by the multiplication of forms and the breaking up and 

 separation of areas. 



The connection between the genus Euphrasia and several of the 

 genera of PMnanthacea — Bellardia All., Odontites Pers., Orthantha 

 Benth., Parentitcellia Viv. (all included in Bartschia by Hook, and 

 Benth.), and Omphalothrix Max. — points to an ancestor from which 

 these have been derived. This ancestor Prof. Wettstein names 

 Falceo- Bartschia. The following scheme exemplifies this: — 



Scheme I. 

 Palc&e - Bartsc}aa. 



^alcrc Eup}vrasva \ 'p. 



ertioury. 



Recent 



l\ 



Siplionidium. Anagrosperma. 



The ancestors of these genera represented a polymorphic genus 

 occupying a wide and isolated area, but this area was diminished, 

 probably during the post-Tertiary epoch, by the low temperature of 

 the ice age, and hence most of these genera have their home now 

 in the Mediterranean and Central Asiatic region. It will be seen 

 that the genus Euphrasia of to-day is sharply divided into sections 

 — the Eueuphrasia section on the one hand, and the Trijidce section 

 on the other ; Section I. being further divided into two subsections 

 — I. Semicalcarat(B ; II. Australes, 



There are evidences to prove that the Australes and Semicalcaratos 

 had common ancestors. E. cuneata, a perennial, in New Zealand, 

 and E. insignis, an annual, in Japan, are morphologically allied. 

 On the other hand, the sections Parvijiora and Grandifiora are only 

 remotely allied to E. insignis. Scheme II. will exemplify this. 



