MONOGRAPH OF THE BEITISH SPECIES OF EUPHRASIA. 331 



Series II. contains eighteen species (see p. 334), characterized 

 as having a comparatively smaller corolla. The relationship 

 of these is more complicatetl. Their areas have a wider ex- 

 tension east and vs^est and nearer to the North Pole, bat they 

 do not reach so far south, circumstances which point to their 

 representatives having an extension, since the tertiary period, over 

 the northernmost portion of the area occupied by the genus, 

 diminished in the north during the ice age, but later on again 

 spreading northwards and occupying isolated and usually mountain 

 areas. It is self-evident that the ancestral species must have been 

 widely distributed in a northern and circumpolar area. The existing 

 species K. latifolia now alone occupies such an area, and it is 

 morphologically and geographically related to the species under 

 consideration. From a parent type similar to E. latifolia sprung, 

 in connection with the dispersion over Europe which followed the 

 post-tertiary ice age, E. curta and E. nemorosa, also the two local 

 species E. occidental is and E. Cebenneiisis ; after the same dispersion 

 there remained on the mountain ranges of Middle and South Europe 

 progenitors from which, fitted to local circumstances, sprung E. 

 Willkommii, E. minima, E. Tatrte, and E. Liburnica. In Northern 

 Europe, in a climate similar to that of the high mountain ranges of 

 South Europe, E. Scotica, so similar to E. winiwa, had its rise. In 

 the Shetland Isles, and the Faroes, &c., we have E. Foulaensis, so 

 nearly related to E. latifolia. In the extreme west we have E. 

 Americana, so nearly related to E. nemorosa. In the extreme east 

 of the area of E. latifolia we have E. mollis, E. multifoHa, and 

 E. Oakesii, similarly derived. 



As regards E. gracilis and E. carulea, we must seek some other 

 origin than that of climatic influence. It has been already observed 

 under the head of "Evolution or Formation of Species" that E. 

 cccrulea and E. curta, though their areas are now isolated, have an 

 analogous origin to that of E. Rostkoviana and E. montana, and 

 there are reasons in favour of a similar origin as regards E. (/racilis. 

 This species occurs within a portion of the area occupied by E. 

 neinoralis and E. curta, and it flowers earlier than either of these ; 

 on the other hand, it is morphologically distinct from both. The 

 conclusion Prof. Wettstein has come to is that E. f/racilis already 

 existed at an earlier epoch and before E. ncmorom and E. curta were 

 differentiated, and that it was the ancestor of a late-flowering species 

 from which both E. nemoralis and E. curta had their origin. The 

 ancestor of Series II. Prof. Wettstein proposes to call E. palao- 

 netnorosa. 



Reverting to E. latifolia, whose ancestor we have learnt to, look 

 upon as the parent of the series under consideration, we see that 

 it is morphologically and geographically allied to E. Tatarica, and 

 consequently to the ancestor of the E. pectinata series, which we 

 have named E. paltEo-jiectinata. Now the old type of E. Tatarica 

 had a very wide range, and we may rightly conclude that it was 

 the origin of the greater number of the species in the group 

 Parvijiora. This type Prof. Wettstein proposes to name E. pala:o- 

 Tatarica ; hence this more ancient form was the parent of the two 



