FLORA OF LIGNITES. 161 



nearly at right angles, they agree very well with those of the 

 existing tree. 



Of bushes, only a species of hazel has hitherto been dis- 

 covered. Its fruits are traversed by deeper longitudinal furrows 

 than the Swiss hazel-nuts ; but this is caused solely by their 

 having lain long in a damp locality ; for the hazel-nuts of the 

 pile-dwellings and of the English bone-caves present the same 

 characters, so that this hazel cannot be separated as a distinct 

 species. What is very remarkable is that the hazel-nuts of the 

 lignites occur in precisely the same two forms as those of the 

 existing species *. The most abundant nut of the lignite epoch 

 is the short-fruited one (Corylus avellana ovata } W., fig. 343) ; 

 it is of a short oval form, and but little longer than broad. Its 

 length is 15 millimetres (or '591 inch), and its breadth is 13 

 millimetres (or -512 inch). Prof. Heer has obtained it from 

 Durnten and Morschweil. In form and size it agrees perfectly 

 with nuts from the pile-dwellings of Robenhausen and with 

 those of the present day. In the second form (Corylus avellana, 

 Linn., fig. 344) the nut is elongate-oval and considerably longer 

 (24 millimetres, or "945 inch) . The length is much greater than 

 the breadth. Prof. Heer has received two specimens from the 

 lignitiferous clays of Morschweil through Prof. Deicke ; they 

 are not distinguishable from those of the pile-dwellings or from 

 those now growing. 



Of herbaceous plants the bog-bean (Menyanthes trifoliata, 

 Linn.) and the common reed (Phragmitis communis, Tr.) are 

 most abundant. Of the bog-bean, or marsh-trefoil, Prof. Heer 

 knows only the seeds small, shining, brownish-yellow, lenti- 

 cular bodies (fig. 345), which are found here and there in great 

 abundance in the lignite at Durnten, Utznach, and Morschweil. 



* The nuts of the Swiss form are almost globular, scarcely compressed ; 

 those of the other are elongate-oval and slightly compressed. In the former 

 the young twigs, the petioles, and the base of the cupule are richly clothed 

 with glandular hairs (as in the Corylus glandulosa, Schoutlew., Corylus avel- 

 Inna ovata, W.) ; in the latter these glandular hairs do not occur or are very 

 scanty, and the cupule is shorter than the fruit. But the short-fruited form 

 is also found with a short cupule, and the hairs scarcely glandular (as at 

 Schambelen), so that this character is not constant. The short-fruited form 

 ripens its nuts earlier, and is therefore known as the (( August nut." 



VOL. ii. M 



