474 THE SOOTY MOULD OF CITRUS TREES, 



(6) The dark coloured hjq)!!* bear gonidia similarly coloured 

 or a little paler, and are usually elliptical and uniseptate. They 

 are ver}'' vai'iable in size, 7|-16 x 5^-8^fi. They are also in moni- 

 liform chains like a Torula, so that this form arises both from 

 the transformation of the colourless and coloured filaments. 



It has been shown by Zopf* that the ordinary joints of the 

 dark coloured hyphaj are capable of germinating when detached. 



(2) Gemnue. — This is a convenient name for clusters of cells 

 which detach themselves and reproduce the fungus. Detached 

 portions of the coloured filaments, consisting of several joints and 

 rounded at the ends, are very common. Also irregular groups 

 of brown cells, which germinate and grow. Just as the genus- 

 name of Torula, Pers., was applied to the moniliform chains of 

 rejDroductive bodies, so the genus-name of C oniothechim, Corda, 

 was given to the irregular groups of cells capable of germination. 

 This form-genus would be represented both by the colourless 

 quadrate bodies already referred to and the brown irregular 

 clusters. 



There are also green mulberry-like clusters of cells which are 

 capable of germination and are really gemmsB, but they naturally 

 belong to the next form. 



It will readily be seen that between the Torula and Gonioih"- 

 cium forms there is no sharp line of demarcation. In the Torula 

 chain a cell may divide in the different directions of space, and 

 thus pass into the other form. 



The multiplication of the fungus is so far amply provided for 

 hj means of gonidia, gemmae and detached joints or mycelia, and 

 even these may pass, according to Zopf, into resting states, if the 

 supply of food slowly diminishes. But while the fungus might 

 multiply abundantly by means of the above-mentioned forms 

 alone, there are various other reproductive bodies to be noticed, 

 so that its rapid spread and extensive diffusion need not excite 

 surprise. 



* L.c. p. 13. 



