268 Excerpta Botanica. 



all points of which the sporidigerous tubes or thecae diverge. 

 Already is the upper part of the sporangium filled with that 

 scobiform substance altogether different from the sporidia, 

 and of a beautiful indigo-blue by transmitted light, but of an 

 opake black en masse, which finally tinges the thecae and spo- 

 ridia of a similar but less deep tint. The cavity gradually 

 enlarges, not only from the swelling of the extremity of the 

 branch, but also from the insensible shrinking of the interior 

 projection formed by the medullary layer of the thallus. 



The nucleus contained in the apothecium differs very 

 slightly from that of other Lichens. It is composed of erect 

 filaments pressed against each other, precisely as in the pro- 

 ligerous lamina of a Lecidea, and united by the intervention 

 of a mucilaginous substance which greedily absorbs water. 

 These tubular filaments, open at their free extremity, have ex- 

 actly the form of the asci or utricules of a Peziza. They are 

 linear, obtuse at the summit, and attenuated into a short pe- 

 dicel at the base, which seems to be the continuation of the 

 filaments of the medullary layer. In their young state they 

 are perfectly transparent, and contain an opaline humour, in 

 which at a later period appear hyaline globules, which are 

 hence only visible on moving the diaphragm of the micro- 

 scope. Gradually these filaments, which can be considered as 

 no other than the true thecae, assume a bluish tint, which be- 

 comes more intense with age, but which, nevertheless, never 

 loses its blue tinge when viewed by transmitted light. 



The sporidia also become more and more apparent in the 

 thecae, being globose or oblong, and arranged in a single se- 

 ries. On the final rupturing of the theca they are set free and 

 become mingled with that mass of black powder, from which 

 however they are clearly distinct, and whose origin it is very 

 difficult to determine, because it exists in the very earliest 

 period of the formation of the apothecium. 



The theca is from the 500th to 600th of a millimetre long, and 

 200th of a millimetre in diameter. The sporidium, either en- 

 tirely spherical or slightly longer than broad, attains when set 

 free a diameter of 100th of a millimetre, and is bounded by a 

 hyaline margin and coloured blue similar to the thecae. 



I cannot assert that paraphyses do not exist in it, but if 

 they do, we are unable to distinguish them from the true 

 thecae, except by their transparence and the absence of spo- 

 ridia in their tube, and every one is aware that these organs 

 are only abortive thecae. 



These observations were made on a specimen of Sphcero- 

 phoron coralloides collected by myself in the Vosges. 



Among the closed Phycece this genus has for its analogue 



