576 
CONTEMPORARY WRITINGS. 
why they are uncultivable. It is a singular 
physiological fact, that all these parasites are 
found to be destitute of medullary rays. Prof. 
Henslow has corroborated M. Decaisne as 
regards the parasitism of the Odontites. De- 
caisne thought, from some analogy of struc- 
ture, that the Sundews would also prove to 
be parasitical on sphagnum, but this seems to 
be opposed to further experience. Another 
well-known plant, unsuspected as a parasite, 
has been pointed out to be such by W. Mitten, 
Esq. ; this is the Thesium linophyllum, whose 
parasitical attachment to leguminous, labiate, 
umbelliferous, composite, and gramineous 
plants, Mr. Mitten has noted. 
" Influence of Light on Vegetation. — 
Signor Zantedeschi, an Italian philosopher, in 
investigating the subject of the influence of 
light, refracted through coloured glasses, on 
the vegetation of plants and the germination 
of seeds, found that every coloured ray is more 
or less injurious to the vegetation of all vege- 
tables; more or less, because the influence is 
not equal on all species of plants. He also 
found by his experiments, that the coloured 
rays of light exercise a beneficial influence on 
the germination of seeds, promoting their 
development. 
DoxENNi d'ete pear. — This is a hand- 
some early pear, with the characters of the 
Doyenne as regards the eye, the segments of 
the calyx, and the thick stalk ; but differing 
essentially in having a soft skin, partially 
coloured with deep red. The flesh is whitish, 
tender, juicy, rich and refreshing, free from 
the disagreeable musky flavour which many 
early pears possess. It commences to ripen 
from the 10th to the 20th of July. It is a 
prodigious bearer. Mr. Rivers of Sawbridge- 
worth states that trees on quince-stocks only 
three feet high have borne this season from 
two to three dozen each. In this variety the 
shoots are clear, olive-yellow, with pale 
brown dots ; leaves elliptic, tapering regularly 
to the point ; the petioles long and slender ; 
the colour of the fruit pale green, streaked on 
the exposed side with deep red. It will form 
a very agreeable addition to the early varie- 
ties already in cultivation. The Doyenne 
d'ete, according to M. Poiteau, has been cul- 
tivated for many years at Nantes ; though, 
till lately, but little known at Paris. It is 
stated in Le Bon Jardinier, that it was in- 
troduced into the nurseries at Paris by M. 
Noisette, in 1830. From various resem- 
blances, it appears likely that it may have 
sprung from the Bellissime d'ete, or Jargo- 
nelle of the French, which is a very different 
pear from the English Jargonelle. 
The Frontispiece. The following are the 
names of the plants which are represented in 
the frontispiece : — Tropseolum speciosum, red ; 
Berberis ilicifolia, orange; Pentstemon Gor- 
doni, pale blue ; and Pleroma elegans, purple. 
These are all of recent introduction, and are 
fully described in the present and preceding 
volumes of the Annals of Horticulture. 
R. CLAY, PRINTER, BREAD STREET HILL. 
