SHEPHERD'S PURSE. 19 
In transverse section the ovary is seen to be very much 
laterally compressed, the replum being across its narrowest 
diameter, and the ovules are very numerous 
on parietal placentee. So quickly do the seeds 
ripen that you will probably find ripe fruit 
and the remains of the fruit on 
the lower part of the same ra- 
ceme that bears the flowers. The 
dehiscence is the same as that 
of the wallflower—viz., by two 
valves, which in this case are 
somewhat boat-shaped; but, as 
5 deen -, - Hig. 13. Obcor- Fie, 14. Trans- 
the fruit is not longer than it is cae ealiaiiey eer eee 
broad, it is called a Silicula, not ofShepherd’s of silicula of 
a siliqua. You will find the seeds Purse. Shepherd's 
are rather small for examination. Purse. 
Compare any of the following plants with the preceding :— 
Sweet Alyssum (Alyssem odoratum).—Note the nearly circular sili- 
cule, containing only two or three seeds in each cell. 
Cress, Candytuft, Honesty, &c. 
Radish.—Note the indehiscent, often fleshy pods. 
Cruciferous plants belonging to many genera, both indigenous and 
introduced, are common in the wild state and in gardens, All have a 
remarkable similarity of floral structure. 
The seeds of the last-named plants are somewhat different 
from those of the cabbage. The Cress may be taken as an 
example. If only old seeds are ob- 
tainable, soak them in warm water, 
and notice that they exude a muci- 
laginous or gelatinous substance. Re- 
move the brown testa, and notice that 
each cotyledon is 3-lobed, and that the Fig. 15. Seed of Gress, in 
radicle lies along the back of one of transverse section, and 
them. In this arrangement of the With hee Wea: Peiioved 
cotyledons they are said to be in- (™#8)- 
cumbent to the radicle. 
3. Pansy, on Huarrszasr (Viola Sp.). 
The Pansy is a highly-cultivated and much-hybridized 
violet. In habit it is a prostrate or trailing succulent herb, 
glabrous in all its parts, and with its stems always more or legs 
4-angled. The leaves are arranged alternately on the stem, 
but notice that at the base of each petiole a pair of leafy 
organs are developed, like wings. These are stipules, and 
all leaves possessing them are called stipulate. It is not a 
common thing to find the stipules so large in proportion to the 
leaf as they are in the Pansy. (You must take care in ex- 
amining plants that you do not mistake small axillary branches 
