432 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
made on the chlorophyll cells with the filtered liquid, and it was 
observed that the chloroplasts became massed at one or both ends of 
the cell ; finally, they lost their shape and colour, and at the end of the 
sixth or seventh day had become an irregular mass. A. L. S. 
Discomycete found on Medlar Fruits.- H. Wormald {Trans. 
Brit. Mycol. Soc ., 1922, 7 , 287-93, 2 figs.). Mummified medlar fruits 
collected from the ground in spring and placed in favourable conditions 
developed a fungus that differed very slightly from Sclerotinia Mespili. 
The writer considers it is probably the origin of the leaf blotch of 
medlar trees, as Monilia fructifications were found on the leaves, but 
all attempts to prove their connexion by inoculation have been unsuc- 
cessful. The author has detailed the development of the apotliecia and 
spores. A. L. S. 
Rhizoctonia Solani as a Potatc-tuber Rot Fungus. — M. Shapo- 
valov {Phytopathology, 1922, 12 . 334-6, 1 pi.). The author has 
proved that the well-known potato parasite Rhizoctonia Solani is also a 
cause of a jelly- type of rot in the tubers. He describes the inoculation 
experiments undertaken by him to discover the cause of the decay. 
A. L. S. 
Lichens. 
Lichens of Somalia. — Carlo Zanfrognini {Nuova Notarisia, 
1917, 28, 145-75). A study of the corticolous lichens of this region 
of Africa. The author has added to his descriptions numerous biological 
and morphological observations as well as critical systematic notes. He 
has given special attention to chemical reaction with various solutions. 
A. Lorrain Smith. 
Lichens of Wolbeck. — F. Tobler ( Hedwigia , 1921, 63, 7-10). 
The author comments on the large number of rare lichens that were 
found by Lahm in the Wolbeck zoological gardens in Westphalia (1856— 
1885). There has been much change since. The trees have increased, 
many of them have been felled, etc., and the lichens have very much 
decreased. He concludes that lichens are very sensitive to the change 
of environment ; chief among the changes is that of moisture, which 
has increased beyond the stage most favourable to lichen growth. 
A. L. S. 
Lichens of Alaska. —Albert W. C. T. Herre {Puhl. Puget Sound 
Biol. Station, 1918-20, 2 , 279-85). About 462 species and varieties 
of lichens have hitherto been enumerated for Alaska ; the present 
list brings the total up to 482. Dr. Herre makes interesting notes 
on some of the families. He looks on the lichen as a physiological 
species — a fungus with an enslaved alga. Several of the species 
recorded are rare plants. A. L. S. 
Growth and Regeneration of the Thallus of Peltigera canina. 
— Cl. Strato ( Hedwigia , 1921, 63, 11-42, 13 figs.). The growth of the 
thallus takes place at the circumference. The isidia may be reckoned 
also as circumference growth, though they grow on the surface. 
