STUDIES IN TEGETABLE BIOLOGY. 



231 



locum habeat. Ab hoc ulteriore differt forma et directione et colore 

 stromatum et peritheciis non proininulis. 



99. PriiENULA adacta, Fee, Ess. p. 74. 



h 



100. Akthracothecittm Manipurexse, Mull. Arg. ; thallus 



flavescenti-pallidus, tenuissiums, lsevis ; apothecia atra, lf-lf mm. 

 lata, sessilia, nuda, hemisphaerica, nonnihil conico-acutata, vertice 

 ininute umbilicato-ostiolata, opaca; perithecium basi valide com- 

 pletion, subtus convexum, lateraliter basi valide productum ; sporae 

 3(-4)nae, fuscae, circ. 110 /* longae et 37 /x latae, crebre cubico- 

 parenchymatosae, series transversales 5-6-1 ocellares. — Juxta Bra- 

 siliense A. aurantium, MiilL Arg. Eevis. Licb. Eschw. n. 7, 

 locandum est, a quo non diversum videtur nisi thallo minus 

 aurantiaco-fulvo, apotheciis paullo altius convexis et sporis ma- 

 joribus. Apothecia distincte minora et convexiora sunt quam in 

 A. Thicaitesii, A. borbonico et A. macrosporo, MiilL Arg. 



101. A. tariolosum:, Midi. Arg. Lich. Afric. occid. n. 52. 

 Pyrenula variolosa, Fers. in Gaudich. TJran. p. 181. 



* 



Studies in Vegetable .Biology. — VIII. An Investigation into 

 the Trufe Nature of Callus.— Part II. By Spencer Le 31. 



MoohV, F.L.S. 



[Read 18th June, 1891.] 

 (Plate XXV.) 



Examination of the Fig. 



In the soft bast of the Fig two methods of closing the sieves 

 of the sieve-tubes are to be noted : the sieves lying upon the 

 abaxial side of the bast are obliterated by means of a substance 

 giving the ordinary dye-reactions of callus, and notably the dis- 

 tinctive Cambridge blue with picric Sands' sblue(Pl. XXV. fig. 1, a). 

 Many of the sieves of tubes lying upon the axial side of the bast 

 ;are clogged with a substance of glassy appearance and dense con- 

 sistence, often possessing a yellow refringence ; this does not 

 stain with picric blue, but, like the stoppers of BaUia, which, 

 when occurring in the form shown at fig. 1 b, it at once recalls 

 to mind, takes a yellow colour with that reagent. It will not be 



