2 20 BritisJi Fitno-i. 



^> 



places tlic parasite was colourless, like the better 

 known species of Saprolegniw; in other places it was 

 rose-coloured, from its absorbing the colour of the red 

 I)<aria. (Smith, I.e.) 



Protomyces concomitans, Berk. (fig. 90). Spores 

 globose, terminal, pale umber, wall thick ; nij-celium 

 thin, septate, here and there colourless. 



Protomijces concomitans, Berk. Gard. Chron. vol. 

 xviii. p. 397, fig. 63 (1882). 



Numerous specimens have occasionally been for- 

 warded to us of a disease which has perplexed culti- 

 vators of orchids as much as the notorious cucumber 

 pest has almost every gardener in the kingdom, and 

 which have iu both cases elicited much interesting 

 information, though unfortunately it appeared after 

 all that the disease was inscrutable, if that were any 

 real satisfaction. There are two forms which ap- 

 peared on orchid leaves, known under the name of 

 black spot, one of which often comes over with im- 

 ported oi'chids, and which evidently commenced 

 while the plants were still in their native country. 

 This was comparatively slow in its progress, though it 

 too often proved in the end fatal. The other was 

 paler in colour, but more speedy in action, and was 

 altogether moister, and it is to this we now call atten- 

 tion. A small leaf of a Dendrobium was lately sent 

 to us which called to mind a matter to which some 

 years since we devoted much time, though without 

 success. Instructed previously by what had been 

 written by De Bary and others, we at once examined 

 the leaf, and at first we found an immense quantity of 

 aleurone (a proteinous matter) under most of the forms 



