176 THE JOURNAL OF BOTANT 



brought out something of even greater interest than that which was 

 sought : viz. extremely thin filaments embedded in the protoplasm, 

 and, as it were, attaching to it the beaded prominence already described. 

 These last stain less deeply than gonidial protoplasm, but nevertheless 

 take a deeper colour that tlie hyphal protaplasm. In preparations 

 kept long in a colouring agent (e. g., during some days in weak solu- 

 tion) the beaded prominences retained their colour, while that of the 

 hyphae was lost on being washed. 



It might naturally be supposed that these beaded prominences 

 were some form of the gonidial protoplasm, but the detailed investi- 

 gations which were undertaken must convince one that they are 

 foreign organisms. As a rule, they are found, as described above, at 

 the periphery of the protoplasm between the gonidial envelopes and 

 contents, Avhile in some cases they are somewhat separated from the 

 protoplasm. In the latter case it may often be observed that thin 

 tilaments extending from them become eiiibedded in the protoplasm, 

 and also that the beaded distention is fixed on a thin stalk. Some- 

 times these are embedded in the protoplasm itself. A circumstance 

 deserving attention is that, in the pale gonidia described above, the 

 contents consist of a knotted and confused mass which, as I believe, 

 is identical with the beaded distentions on the protoplasm of the 

 green gonidia. On thin microscopical sections showing beaded dis- 

 tentions on their protoplasm the following pictm-e is presented with 

 the utmost distinctness : the gonidial protoplasm is intersected by 

 fine threads forming in places knots of every size and shape ; the 

 beaded distentions are, apparently, derived from similar knots of 

 filaments piercing the gonidial protoplasm, but differ in their much 

 larger size. They are distributed especially on the peripherj^ of the 

 protoplasm. Their generally rounded shape becomes irregular, owing 

 to the filaments which attach them to the protoplasm. 



The morj^hology of the beaded distentions described above and 

 their connection with the network of intracellular haustoria, their 

 existence in gonidia, whose contents are obviously wanting, are 

 sufficient in my opinion to prove that these distentions are not a 

 formation of the gonidial cells themselves. The signs i'ndicated, and 

 the similar staining reactions with that of tiie hyphal protoplasm, 

 must fix them as products of intracellular life. Something in the 

 natui-e of the beaded distentions appears in the germination of spores 

 in certain genera of lichens having large spores,-such as Thelotrema, 

 Megalospora, Ochrolechia, and Pertusaria, although so far it is 

 impossible to draw a complete analogy between the formation I have 

 described and the globular shoots on the germination of spores of the 

 above-mentioned plants, but the analogy demands recognition. 

 According to the investigations of De Bary the spores of the above- 

 named lichens on leaving the endospore develop shoots which take a 

 globular form. These shoots as they further develop burst through 

 the exospore as promycelia, the threads of which, if they do not come 

 in contact with algal cells become part of the substratum. According 

 to the observations of A. Moller, two types of hyphal threads arise 

 from the promycelium which are quite distinct in physiological 

 function. Some typical threads become embedded in the substratum. 



