SPECIAL MORPHOLOGY: LICHENES. 157 



Ag. deliciosus the milky juice is certainly present, as I have indicated; but 

 some have insisted that they also found true lacteals in Fungi, a state- 

 ment that for the present I must leave undisputed. The most remarkable 

 thing in the Fungi is at all events the great difference in the nature of 

 the cell-membrane, which, at least, according to Payen's investigations, 

 consists of common cellulose. The state of decomposition into which 

 the various species of Coprinus pass in the course of a few hours, 

 becoming converted into a black, highly carbonaceous fluid, is very 

 striking indeed. But we are still deficient here in accurate observations. 

 Telephora hirsuta contains, according to Schmitz (Linnsea, 1834, p. 438.), 

 beautiful octoedric crystals (oxalate of lime ?) 



III. LICHENES (LICHENS). 



86. Whilst the Fungi form their spores in a thread-like pro- 

 longation of the parent cell, and separate by constriction across 

 the neck, the Lichens develope many spores simultaneously (many 

 of them double spores) in the interior of a larger parent cell. We 

 thus have a clearly defined limit drawn between the two groups. 



Many nuclear Fungi (Pyrenomycetes) cannot, or at least not easily, 

 be distinguished, without previous acquaintance with them, from many 

 Lichens (as, for instance, of the groups Idiothalami and Gasterothalami). 

 They correspond so closely with Lichens, with respect to the law of the 

 development of their spores, that I, at least, for my part am unable 

 to separate them. But the same may be said of the discoid Fungi 

 (Discomycetes). Most of the smaller species of Peziza are altogether 

 deficient in any characteristic by which they may be distinguished from 

 the apothecia of Lichens as a peculiar order, especially if we compare 

 with them the soft gelatinous substance of the fruits of the Col/ema, 

 which so frequently occur without any thallus. I therefore combine 

 them with the Lichens, as I thus gain from the peculiar, essentially- 

 distinct history of their development a well-marked characteristic to 

 separate the two groups. After the admirable observations and inves- 

 tigations of Camille Montagne*, we can no longer doubt that Lichina 

 (Ag.) belongs to the true Lichens. 



87. The spores of Lichens develope, in a way of which we are 

 ignorant, cells mostly of roundish form, which spread out flat upon 

 the subjacent surface (protothallus) : by degrees larger globular 

 cells are formed upon this, which the upper and under surfaces, be- 

 coming more closely connected, and the lower face a little elongated 

 in a vertical direction, form a plant (thallus Aut.) of crustaceous 

 aspect (thallus crustaceus), the outline of which appears usually very 

 irregular and dependent upon accident. 



In other forms the Lichen tissue is developed between the upper 

 and lower layer, and then the plant assumes more definite and 

 independent lobed forms (tliallus foliaceus), the outline of which is 

 generally circular. Irregular bundles of interwoven tissue often 

 separate themselves from the lower surface, serving as organs of 



* Ann. de Sc. Nat. 1841, xv. (Mars), p. 146. 



