286 ANATOMY OF JJ'idd y'ui gto )uo AND CalHtvis. 



bast. The former is composed of a single layer of bast fibres, 

 the latter of three layers of thin-walled cells, of which the 

 middle layer represents the functional sieve tubes. A small 

 part of the phloem of Callitris robiista is shown in Figure ii, 

 and the same drawing would serve equally well to ilhistrate 

 either of the other species examined. 



I am glad to acknowledge advice and criticism on certain 

 points from Mr. W. C. Worsdell, F.L.S., who also cut the sec- 

 tions from which Figures 8 and 9 were drawn. I have also to 

 than Messrs. J. J. Boocock and G. A. Zahn, of the S.A. School 

 of Forestry, for collecting the material of Callitris on which 

 the present account is based, and Mr. G. A. Wilmot, M.F., for 

 permission to collect this and other material in the Government 

 Plantations at Tokai. 



Summary and Conclusions. 



In two species of Callitris thickenings of the cell wall are 

 found to occur in connection with the bordered pits, both in 

 the wood and in the transfusion tracheids. 



Concentric rings of secretory cells are also characteristic of 

 the wood of these two species. 



In the leaf of Callitris a layer of thick-walled hypoderm is 

 found. 



In Callitris verrucosa very pronounced xerophytic characters 

 are met with, but these are less marked in C . robusta. 



In Widdringtonia ciiprcssoides no irregular thickenings of 

 the cell wall occur in connection with the bordered pits, either 

 in the wood or in the transfusion tracheids. 



Peculiar tracheids are, however, found, in this species, with 

 elongated bordered pits on the tangential walls. 



No concentric rings of secretory cells are met with in the 

 wood, and in the leaf no hypoderm is found. 



As far as conclusions may be drawn from so small a number 

 of species, the genus Widdringtonia seems to be sharply separ- 

 ated in anatomical characters from the genus Callitris. 



RHODESIA MOTHS.— At the meeting of the Zoological 

 .Society held on the ist March, Sir G. F. Hampson submitted 

 a list of moths collected by Mr. S. A. Neave in Northern 

 Rhodesia and in the Katanga district. The descriptions include 

 close on to 200 hitherto undescribed species. The moths for the 

 most part resemble those of W'est Africa, together with many 

 East African and Mashonaland types. Owing to the topo- 

 graphy of the area considered the fauna presents considerable 

 uniformity, and is tropical African in character, the high moun- 

 tain forms and those characteristic of the drier regions being 

 unrepresented. 



