CELLS AND CELL PRODUCTS 213 



B. Contents and Products of the Fungal Cells 



a. Cell-substances. The cells of lichen hyphae contain protoplasm 

 and nucleus with glucoses. It is doubtful if starch has been found in fungal 

 hyphae ; it is replaced, in some of the tissues at least, by glycogen, a carbo- 

 hydrate (Ce Hjo O5) very close to, if not identical with, animal glycogen, a 

 substance which is soluble in water and colours reddish-brown (wine-red) 

 with iodine. Errera' first detected its presence in Ascomycetes where it is 

 associated with the epiplasm of the cells, more especially of the asci, and he 

 considered it to be physiologically homologous with starch. He included 

 lichens, as Ascomycetes, in his survey of fungi and quotes, in support of his 

 view that lichen hyphae also contain glycogen, a statement made by Schwen- 

 dener^ that " the contents of the ascogenous hyphae of Coenogonium Linkii 

 stain a deep-brown with iodine." Errera also instances the red-brown reaction 

 with iodine, described by de Bary', as characteristic of the large spores of 

 Ochrolechia {Lecanora) pallescens , while the germinating tubes of these spores 

 become yellow with iodine like ordinary protoplasm. Glycogen has been, 

 so far, found only in the cells of the reproductive system. 



Iodine was found by Gautier* in the gonidia of Parmelia and Peltigera, 

 i.e. both in bright-green and blue-green algae. The amount was scarcely 

 calculable. 



Herissey' claims to have established the presence of emulsin in a large 

 series of lichens belonging to such widely separated genera as Cladonia, 

 Cetraria, Evernia, Peltigera, Pertusaria, Parmelia, Ramalina, and Usnea. It 

 is a ferment which acts upon amygdalin, though its presence has been 

 proved in plants such as lichens where no amygdalin has been found*. 

 Diastase was demonstrated in the cells of Roccella tinctoria, R. Montagnei 

 and oiDendrographa leucophaea by Ronceray' who states that, in conjunction 

 with air and ammonia, it forms orchil, the well-known colouring substance 

 of these lichens. Diastatic ferments have also been determined^ in Usnea 

 florida, Physcia parietina, Parmelia perlata and Peltigei-a canina. 



b. Calcium Oxalate. Oxalic acid (C2H2O4) is an oxidation product 

 of alcohol and of most carbohydrates and in combination is a frequent 

 constituent of plant cells. Knop' held that it was formed in lichens by the 

 reduction and splitting of lichen acids, though, as ZopP" has pointed out, 

 these are generally insoluble. Hamlet and Plowright" demonstrated the 

 presence of free oxalic acid in many families of fungi including Pezizae and 

 Sphaeriae. The acid combines with calcium to form the oxalate (CaCgOj), 

 which in the crystalline form is very common in lichens. In the higher 



' Errera 1 882. ^ g^hwendener 1862, p. 231. ^ De Bary 1866-1867, p. 211. ^ Gautier 1899. 



* Herissey 1898. ' Czapek 1905, II. p. 257. >■ Ronceray 1904. * Zopf in Schenk 1890, p. 448. 



8 Knop 1872. " Zopf 1907. " Hamlet and Plowright 1877. 



