INTRODUCTION TO CEYPTOOAMIC BOTANY. 



373 



the naked fruit as spermatia ; in those he regards them as stylo- 

 spores. But of this more hereafter. But besides these, there are 

 abundant globular bodies of a vegetable green produced from 

 the threads of the thallus. The origin of these has only very 

 lately been studied. I had myself a good opportunity of ascer- 

 taining their development from the threads of the mycelium, 

 in specimens developed within the vessels of pine wood picked 



rig. 78. 



a. Wood cell of White Spruce much decomposed, filled with myce- 

 lium of Parmelia parietina, bearing gonidia. 



b. Spermatia on fertile threads of Umhilicaria pustulata. 



c. Ditto of Uroeolaria calcarea. 



d. Ditto of Urceolaria cinerea. 



All highly magnified. The three latter after Tulasne, to whose trea- 

 tise on Lichens, in Ann. d. Sc. Nat, 1852, every writer on the subject 

 must be deeply indebted, and of which I have largely availed myself. 



e. Threads and spermatia springing from wall of spermatogonium of 

 Borrera ciliaris. From a sketch by Mr. G. H. Hofiinan. 



up by Captain Inglefield in the arctic regions, and figures have 

 lately been published by Speerschneider in the Botanische 

 Zeitung for 1854.* In many Lichens these bodies obtain 

 access to the external air by means of rents in the upper 

 surface, of more or less regularity, and are washed off after 

 losing a little of their vivid colouring. The colour origin- 

 ally is always green, but it is modified by external circum- 



* According to his observations they spring partly from the medul- 

 lary layer, and partly from the tissues with which it is in immediate 

 connection. 



