«o THE ORCHID REVIEW. 



t. 322). Mr. Thompson's plants are out of this importation. The species 

 is allied to O. gloriosum, but is markedly different in its long, acuminate, 

 somewhat undulate segments, and other structural details, and in colour. 

 The ground colour is very light yellow or greenish yellow, and the spots 

 ■cinnamon brown, with a darker brown blotch in front of the very pale disc, 

 .these colours affording a very pleasing contrast. Mr. Stevens states that 

 .the plants grow and flower very freely, and they have been in the collection 



GALLS ON ORCHIDS. 



'Orchids are not particularly subject to the attacks of gall-producing 

 insects, and it may be interesting to note that MM. Darboux and Houard, 

 in a work entitled Catalogue systematise des Zoocecidies dc V Europe et du 

 Bassin Mcdiicrranccn, include the genera Cattleya, Dendrobium, Disa, and 

 ■Odontoglossum as subject to such attacks. It is curious to note that not a 

 s ingle indigenous Orchid is mentioned, and one rather wonders why culti- 

 vated exotics should be included in a work bearing such a title. This, 

 -however, is a detail. Under Cattleya we find the too well known Isosoma 

 Orchidearum (the Cattleya fly, a member of the Tenthredinideae) as having 

 been observed on Cattleya amethystoglossa, C. Bowringiana, C. Gaskelliana, 

 C. labiata, C. Mossist, C. Trianse, and C. sp. A rounded gall of the size of 

 a pea, occurring on the aerial roots of this genus, is also mentioned as the 

 work of one of the Cecidomyidese. The Cattleya fly seems able to 

 accommodate itself to circumstances in our collections, for Dendrobium 

 •densiflorum, D. formosum, D. Phalaenopsis, and D. undulatum are all 

 mentioned as subject to its attacks. Another gall, of the size and form of 

 a grain of wheat, has been observed on an unidentified species of Dendro- 

 •bium; the gall has an ovoid cavity, containing an orange-yellow larva, 

 "belonging to one of the Cecidomyideae. Disa grandiflora is mentioned as 

 having been attacked by a disease analagous to the " maladie annulaire " 

 of the hyacinth, possibly the work of the same insect, Tylenchus 

 •devastatrix, a nematoid worm. Lastly the leaves of a species of Odonto- 

 glossum are said to have been disfigured by small black and rounded 

 protuberances, the work of an Anguillulide. It is hardly necessary to add 

 that Orchidists will include all the above under the genus "pests" should 

 they appear in their collections, and treat them accordingly. It is useful to 

 know the form in which these maladies may appear, and the knowledge 

 may sometimes enable the mischief to be detected before it has assumed 

 .undue proportions. 



