119 
APPENDIX 1. 
I. CITRUS SPECIES CULTIVATED IN AUSTRALIA. 
Citrus aurantium, L.—var. bergamia, Risso—Bergamot Orange. 
var. bigaradia, Loisel—Bitter Orange, 
var. deeumaua, Murr.—Pomelo and Shaddock, 
var. dulcis, Pers.—Sweet Orange, 
var. nobilis. Lour.—Mandarin or Tangierine. 
Citrus japonica, Thun.—Cumquat. 
Citrus medica, L.—var. cedra. Link—Citron. 
var. limetta, Risso—Lime 
var. limonum, Risso—Lemon, 
var. lumia, Risso—Sweet Lemon. 
Citrus trifoliata, L.—Trifoliate-leaved Orange or Hedge-lemon of Japan. 
II. NATIVE CITRUS SPECIES. 
Citrus australasioa, F. v. M.—Finger-lime. 
Citrus australis, Planch.—Native Orange. 
Citrus inodora, Bail.—Queensland Lime. 
With reference to this last species, Mr. Bailey remarks—“ This new 
species of Citrus is well worthy of cultivation for its fruit, which is juicy 
and of equal flavour with the West Indian Lime.” 
APPENDIX 2. 
Letter from L. 0. Howard, Pli. D. 
United States Department of Agriculture, 
Division of Entomology, 
Washington, D.C., 
2Gth November, 1898. 
Dear Sir, 
Your letter of the 10th of October, asking for the description of a method 
of treatment for nursery stock which will insure the destruction of insects 
in any stage, and of fungus diseases, duly received. I regret to inform 
you that an absolutely reliable and universally elective means of disinfec- 
tiou of nursery stock has not been discovered. The gas treatment can be 
used at a very great strength on dormant nursery stock, but it will not, as 
a rule, kill the eggs of insects, especially where they may be protected by 
overlying more or less impenetrable matter, as beneath the dead mother 
scales in the case of Cocciih©* It is, therefore, by far the most effective 
means of disinfection now known. Many plants can be immersed in 
water at a temperature above 150° Fahrenheit for several minutes without 
particular injury to the plant, and this treatment is even recommended for 
disinfection from certain insects. Where it can be practised it is probably 
even more efficacious than gas. It is used in this country for the treat¬ 
ment of root stock presumably iufested with root lice. 
In the matter of plant diseases I am not an authority, but undoubtedly 
there are diseases which invade the tissues of the plant, and which no 
treatment short of the pruning knife or fire will remedy, and as they are 
not always discoverable in the early stages, an absolute preventive of in¬ 
troduction by inspection and treatment is necessarily impossible. The 
long experience with the hydrocyanic acid gas in California has early 
demonstrated its practical efficiency, even though absolute certainty of 
I 2 
