STORAGE ORGANS 195 



droplets about. Insects may become contaminated by the sticky spores 

 and thus carry the fungus from place to place. 



Chlamydospores are very frequent in many of the orders of the Carpo- 

 myceteae. They arise by the rounding up of mycelial cells, filled with 

 food substances, and the production of a thick wall. They may be inter- 

 calary or terminal, single or two to many in a series. In some fungi they 

 germinate promptly, in others they are able to remain dormant a long 

 time. 



The mycelium usually consists of long, slender branching hyphae with 

 terminal growth. Usually the cell is several to many times as long as wide. 

 The septa are centrally perforated by a pore which may be small or may 

 approach in size the perforations found in the septa of the Florideae. In 

 the order Laboulbeniales the cells are short and broad and the whole 

 structure does not resemble typical mycelium. In the Phycomyceteae 

 where septa do occur they are formed, as in the Higher Fungi, by an 

 annular growth on the inner surface of the longitudinal wall which pro- 

 gresses inward, but instead of leaving a central pore it continues its 

 development until the opening is obliterated. 



Buller (1933) and Brodie (1942) give the diameter of these openings 

 in the Carpomyceteae as of the order of 1.0 to 1.5 n. The flow of cytoplasm 

 through the septa has been observed by Ternetz (1900) and by Buller, 

 sometimes to carry small vacuoles with the flowing stream. The rate of 

 flow through the hyphae varies but Ternetz observed the speed of 10.5 

 cm. per hour in Ascophanus carneus (Pers.) Boud., and Buller the speed 

 of 6 cm. per hour in Firnetaria fimicola (Roberge) Griffiths and Seaver. 



Storage Organs 



In many species in the class Basidiomyceteae peculiar structures called 

 "clamp connections" occur at each septum. These will be described in 

 connection with that class. The mycelium may be packed together 

 laterally into compact strands with a firm hard outer layer, forming long 

 "rhizomorphs" which may extend many meters. In many species storage 

 organs, sclerotia, are formed in which the hyphae are packed tightly 

 together and the short cells are pressed mutually to become polyhedral 

 in shape. The adjacent cells adhere to form a parenchyma-like tissue, 

 more properly called pseudoparenchyma. True parenchyma which is 

 rare in the fungi consists of moderately thin-walled ceUs, isodiametric or 

 at least not greatly elongated, which have arisen through the division in 

 various planes of larger cells or of small meristematic cells. The walls 

 separating these cells are the septa between two daughter cells. Pseudo- 

 parenchyma arises from closely crowded or interwoven hyphae divided 

 by cross septa into rather short cells which by their enlargement and 

 mutual pressure become similar in appearance to the cells of true paren- 



