64 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
number of rare and valuable North American conifers, obtained 
from Oregon, and shipped directly to Copenhagen. From these 
seeds, kept in glass jars, and exhibited at an Exhibition in 1888, 
examples of different AZegastigmus species made their appearance, 
with no trace of any other insect save a single Dipterous insect 
from Adies concolor. Borrits goes on to say in his letter: 
“It is worthy of mention that in the preceding year these 
valuable seeds could not be obtained at all, because, as was 
reported from Oregon, they ‘had been destroyed by a worm.’” 
Riley received from Borries Megastigmus adults from the follow- 
ing species—Abzes magnifica, A. concolor, A. amabilis, A. grandis, 
Tsuga Hookeriana, Abies Mariesti (a Japanese species). Riley 
refers the species from the first four trees to probably AZegastigmus 
pinus, Parfit, this being a Californian species. Nitsche, too, 
has chronicled the finding of the larva of a large undescribed 
Megastigmus from the seed of the Californian Adies amabilis. In 
the discussion which followed the reading of Riley’s paper, Dr 
Howard still maintained that the J/egastigmus larve were 
parasitic on some insect, and that they had only taken to the 
seed after devouring the host-larve, whatever these might be. 
IMPORTANCE OF THE QUESTION. 
The question as to whether J/egastigmus is p2rasitic on insects, 
or is a direct enemy to the plant or tree, is no mere academic 
one, but is a question of great significance in practical work: for 
according to the answer given we will either treat A/egastigmus 
as a useful ally against a plant and tree enemy, and accordingly 
protect it, or else recognising it as an enemy, we shall have 
to wage war against it. With the importance of this question 
in mind, and apart from the preceding evidence which seems 
to warrant the view that Megastigmus spermotrophus is a direct 
enemy of the tree, I dissected with great care many of the 
Douglas fir seeds, and in no dissection did I find a trace of 
an enemy other than the Megastigmus, while all the insects 
I bred out were, similarly, Megastigmus. Mr Crozier’s evidence 
is of great value on this point. Hundreds of Megastigmus, and 
Megastigmus alone, have been found by him escaping from the 
infested Douglas fir seeds. 
As we have material, arrangements have been made whereby 
we hope by direct experiment to trace the life-history of the 
