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DESCRIPTION of 



THREE SPECIES of ANGUILLULIDZE, observed 



in DISEASED PSEUDO-BULBS of TBOPICAL 



ORCHIDS. 



By Dr. J. G. de Man, 



Of Ierseke, Zeeland, Netherlands. 



Plates III— Y. 



In the beginning of February, 1894, Dr. J. Ritzema 

 Bos, of Wageningen, Netherlands, sent me some diseased 

 pseudo-bulbs of tropical orchids, belonging to the genus 

 Calanthe, R. Br., begging me to inquire, together with 

 him, into the cause of the disease. We did not succeed 

 in discovering it, though it became very likely that some 

 fungus which propagates in the tissue of the said pseudo- 

 bulbs ought to be considered as the origin of the pest. 

 In the disorganized tissue, however, which in some 

 pseudo-bulbs was changed into a humus-like substance, 

 several species of Nematode worms were observed : three 

 of the latter will be described by me in the following 

 pages. 



The pseudo-bulbs had been sent to Mr. Ritzema Bos 

 from the greenhouses of the Duke of Westminster, at 

 Chester, England. Some belonged to Gal. vestita, Wall. ; 

 most of them, however, to Gal. Veitchii, a hybrid form 

 between the said Gal. vestita and Gal. rosea. The species 

 of this genus of plants are found in India and Australia, 

 so, e.g., Gal. vestita in Burma. I therefore at first 

 supposed that the original habitat of these worms was 

 not Europe, but that they should prove to have been 

 imported, in the tissue of the plants, from India, especially 



