822 REPORT—1904. 
10. The Inheritance of Susceptibility and Immunity to the Attacks of 
Yellow Rust. By R. H. Birren, J.A. 
Evidence was brought forward to show that the liability to certain diseases is 
inherited, and the results of crossing together races of wheat relatively immune 
and highly susceptible to the attacks of Puccinia glumarum were described in 
detail. It appears that susceptibility is dominant over immunity in the hybrid, 
whilst in the second and third generations the immune, or recessive, forms are 
found in approximately the Mendelian ratio of 1 to 3. 
1). Infection Experiments with various Uredinee. By Miss C. M, Gipson, 
The following list summarises the results of successful and doubtful cases of 
the entry of the stomata by the germ tubes of the spores employed :— 
Result 
Spores Species of Fungus from Host 
Uredospores | Uredo chrysanthemi Chrysanthe- | R. ficaria | Enter freely 
MUM | 
| Alcidiospores | Phragmidium rose- | Rosa i ; 
alpine 
AMecidiospores | Uromyces Pow Ranunculus a | 3 
TEPens 
Aicidiospores Peidium Buniti | Bunium re | Negative? 
Alexuosum | 
AXicidiospores Puceinia Poarum Tussilago | Caltha Enter freely 
Sarfara palustris 
Uredospores Tromyces geranii Geranium 9 ¥ 
pyrenaicum 
Aicidiospores Puccinia Menthe Mentha as Enter not 
very freely 
| Uredospores Puceinia hieracii Carduus ? Caltha | Enter freely 
| 
| Jicidiospores Phragmidium Poterium iy 2 or 3 doubt- 
sanguisorbe sanquisorba ful entries 
Uredospores Puceinia glumarum Triticum 3 1 certain 
vulgare entry 
From the above results it is evident— 
1, That the germ tubes from the spores of any uredine may enter almost any 
lant. 
‘ 2, That the attractive substance causing entry is not specialised in each species, 
but is something common to all plants. 
3. That the entrance of the stoma by any germ tube cannot be taken as an 
index of the infective capacity of that germ tube. 
The paper also dealt with some experiments on chrysanthemum rust and time 
experiments on the germinating power of uredo- and :cidio-spores. 
12. On the Normal [Histology of the Uredo of Puccinia glumarum. 
By T. B. P. Evans, 
13. Pineapple Galls of the Spruce. By E. R. Burpon, B.A. 
The galls are caused by the hibernating generation of certain aphid belonging 
to the genus Chermes. a 
In the autumn a Chermes larva drives its long proboscis into the stem of the 
ee 
