Morphology. 5 



Geaster Jtijgrometricus, where tlie wall in transverse 

 section is seen to consist of from tliree to five layers 

 or lamellm. In many fungi tlie thickened walls of 

 the hyph^e become partly dissolv^ed on the outside, and 

 form a gelatinous mass when moist, becoming horny 

 and rigid when dry. This idea is carried to the 

 extreme in Tremellinese, where a section under the 

 microscope presents the appearance of a densely inter- 

 woven mass of very fine threads imbedded in a homo- 

 geneous gelatinous substance. The apparent fine 

 threads are the very much reduced cavities of the 

 interlaced hyph^ containing a finely granular sub- 

 stance, the gelatinous matter consists of the dissolved 

 cell-walls that have completely lost their individuality 

 and form a homogeneous mass. Fme pits are present 

 in the walls of certain hyphoe in the genus Lyco- 

 'perdoiij and De Bary states that in the mould called 

 Dactylium macro sporum, there is a large pit in the 

 centre of the thick transverse septa similar to what is 

 found in the transverse septa of the Floridex or red 

 sea-weeds. It has already been stated that the 

 tissues of fungi consist of more or less parallel or 

 intricately interwoven simple or branched hyphi^, 

 and that increase in size depends on the formation of 

 new cells at the tips of the hyph^e only, and this state- ^ / «—* 

 ment generally holds good, but cannot be universally -^ /b<Q£j/ti 

 applied, as in many well-known instances we get a ^ ^ •— <-• 

 tissue formed from a single cell dividing in different 

 planes as in the case of flowering plants, and conse- 

 quently producing true fundamental or cellular tissue. 

 In many fungi the mycelium becomes concentrated at 

 certain points into a solid mass called a sclerotium; 



