THE: AUSTRALIAN NATURALIST. 121 
quite a distinet species, not even closely related to the sheep fly 
parasite. In examining these parasitised spider cocoons they 
were found to contain from 26 to 85 perfect little wasp pupae. 
In captivity in a roomy test tube the freshly emerged spider 
chaleid wasps when placed with some fresh spider cocoons im- 
mediately turned their attention to the cocoons, and at once set 
to-work to pass their eggs through the silken covering. 
This discovery is an interesting glimpse of Nature’s method 
of control, in the spread of the Red-backed Spider. This hand- 
some jet-black spider, with its briliant splash of bright warn- 
ing red on the middle of its rounded body, is very common all 
over Australia, making its home in sheltered dry corners of 
sheds and outhouses, under heaps of fencing posts, and a very 
favourite locality is an overturned empty case or box. 
GERMINATION OF CHOKO SEED. 
By Miss A. A. Brewster. 
The fruit of the Choko is a one-seeded berry, the seed being 
embedded in a fleshy pericarp (fruit covering). On placing a 
thin section under the’ microscope, the cells are seen to be 
crowded with starch grains which turn blue when treated with 
a drop of iodine solution. The fruit also contains much mois- 
ture. Botanically the seed is normal in structure, consisting of 
the embryo enclosed in a testa or skin. As germination of the 
embryo proceeds there appear a plumule or first shoot, a rudi- 
mentary radicule or primary root and two large fleshy cotyle- 
dons or seed leaves. The cotyledons quickly enlarge, and par- 
tially push out of the fruit. The testa does not enlarge, but 
divides into two plates, which remain within the fruit adpressed 
to the enclosed portion of the cotyledons and act as foodsand 
moisture transporters to the growing embryo, from the stores 
contained in the fruit. On account of the abundant supply of 
water contained in the Choko fruit, the radicle, which is’ usually 
the first part of a seed to grow, and the main function of 
which is to furnish a supply of this essential, is rudimentary. 
The shoot grows first, and later the secondary roots burst from 
the rudimentary radicle. ; 
