1365.] Botany and Vegetable Physiology. 83 



Nylander have erroneously referred the plant) contains only eight 

 spores in each ascus. 



Dr. von Fritich, of Zurich, enumerates the following species of 

 Lichens, as found by him on Teneriffe : — Lecanora flava var. oxytona ; 

 L. liparia, Ach. ; L. orcina, Ach. ; Parmelia elegans var. tenuis ; P. den- 

 dritica, Pers. ; P. parietina var ectanea, Ach. ; P. caperata, Ach. ; P. 

 caesia, Hoffrn. ; P. speciosa, Wulf. ; Gyrophora vellea, var. spadochroa, 

 Ach. ; Lecidea geographica var. atrovirens ; Cladonia furcata var. ran- 

 giforniis. 



Professor Koernicke, of Welden, near Konigsberg, describes a 

 species of Melampsora which does great injury as a parasite to fields 

 of flax in Prussia. Urocystis occulta is another parasite which 

 destroys the rye in Prussia. 



The vegetable nature of Diatoms has been inferred in part from 

 their mode of reproduction, viz. by conjugation, as in Algse. Of late 

 the process has been actually observed in Navicula serians, N. rho- 

 moides, and Pinnularia gibba. 



In leaf venation we usually find that the lateral veins in lobed or 

 toothed leaves are placed in the centre of the lobes, and correspond 

 to the extremities of the teeth. In some cases, however, the secondary 

 veins correspond to the sinuses of the leaf, as in Coldenia procumbens, 

 Crataegus Oxyacantha, and Rhinanthus. Alphonse de Candolle also 

 found the same to be the case in several species of Fagus (beech) as in 

 Fagus Gunnii, Hook, and F. antarctica, Fost. Species, however, which 

 are nearly allied, sometimes present different kinds of venation. In 

 some species the same leaf shows this phenomenon, — some of the veins 

 going to the teeth, others to the sinus. This is seen in Fagus alpina, 

 Poepp. and Endl., and even sometimes in the common beech (F. sylva- 

 tica), and F. procera, Poepp. and Endl. This direction of the venation 

 furnishes characters for distinguishing the Fagus Sieboldii of Japan 

 and the Fagus ferruginea (_F. sylvestris, Mirb.') from the Fagus sylvatica 

 of the Northern European continent. In the beech of the United 

 States, as well as that of Japan, all the lateral ribs and veins distinctly 

 run in straight lines to the extremities of the teeth, which are always 

 distinct and pronounced. In the European beech, not only are the teeth 

 less distinct, and pass often into simple undulations, but the ribs are 

 directed rather towards the sinuses, or, at least, are curved near the 

 teeth, except those at the siunmit of the leaf. Other species having 

 lateral veins directed to the dentations are Fagus obliqua, Mirb. F. 

 Dombeyi, Mirb. F. fusca Hook, and F. Cunninghamii Hook. Pale- 

 ontologists should beware of laying too much stress on the venation as 

 indicating genera in fossil plants. 



In the species of Sonchus, Professor Wolfgang, of Frauenfeld, finds 

 that the pappus is formed of three or four rows of cellules, the oldest 

 part of the hairs being their extremity. The very fine pappus of 

 Sonchus under the microscope presents at its point asy stem of small 

 hooks, formed usually of five or six cellules disposed in eight lines, 

 recurved externally in the form of a hatchet. This may be a useful 



