832 MONOGRAPH OF THE BRITISH SPECIES OF EUPHRASIA. 



series we have been considering, viz. Series I. E. fal(eo-j)cctinata, 

 and Series II. E. palao-nemorosa : the former comprisiiig species 

 with flowers comparatively larger and fitted both for cross- and 

 self-fertilization, but for the former alone at the time of the 

 opening of the flowers ; the latter comprising species with a 

 more northern range, and with flowers comparatively smaller 

 and fitted for self-fertilization, but in which cross-fertilization is 

 not excluded. 



Series III. — I pass by E. (/rand (flora, E. niicrantha, and E.pul- 

 chella as having less connection with British species, to consider those 

 species of the group Parvijlora which have, in common, glandular 

 hairs on the leaves and calyx, and which probably have a hybrid 

 origin. The species are six in number, viz. E. kirtdla, E. drnso- 

 calyx, E. Jaeschkei, E. Regelii, E. hrevipiia, and E. tenuis, but only 

 one — E. hrevipiia — is British. E. hirtella is a peculiarly marked 

 and distinct species. It has a very wide distribution, similar to and 

 perhaps even wider than that of E. Tatarica ; this fact, taken 

 together with its absence in South Europe, except in small and 

 isolated areas, in the Pyrenees, South-Avest Alps, the Balkan 

 Peninsula, and the Siebenbiirger, point to this as a typical repre- 

 sentative of those species, the area of which, though widely extended 

 in tertiary times, was reduced in Europe during the post-tertiary 

 glacial epoch. We therefore look upon E. hirtella as an old and 

 unaltered connection of E. palcco-pectinata. 



E. hrevipiia, the only species which is British, comes morpho- 

 logically near to the E. palao-pectinata series, but it has glandular 

 hairs. May it be a hybrid between E. pectinata and E. hirtella, or 

 between E. stricta and E. hirtella, as these species are now found in 

 company in the Southern Alps ? But E. Inrtella is not found in 

 Northern Europe, and Prof. Wettstein thinks it improbable that, 

 having such an origin, E. hrevipiia could have spread northwards, 

 or that it was a hybrid between E. hirtella and any member of the 

 E. pala;o-pecti)iata series. The supposition that it had a more or 

 less distinct origin in the south from that which it had in the north, 

 and that two forms so similar were originated that they cannot now 

 be distinguished one from the other, is also improbable. A more 

 probable supposition is that E. hirtella was not one of its parents, 

 but that it is a hybrid between E. Ptostkoviana and E. stricta. There 

 can be no doubt that it had its origin far back in time, as is 

 betokened by its widely-extended area, also by the occurrence in 

 the south of the closely-allied species E. tenuis, which has the same 

 relation to E. hrevipiia as E. montana has to E. Bostkuvlana, and 

 E. ccBVulea to E. curta. 



Scheme III. shows at a glance the phytogeny of the species 

 contained in the group ParvifiorcB. 



