THE ENTOMOLOGIST. 65, 
of the hitherto described species of Synergus have not been 
clearly distinguished from each other. He has many proofs 
that two certainly different kinds of lodgers live together in 
one gall; and he gives in short the result of his observations 
on C. lignicola. He isolated about four hundred galls of this 
species. From most of these only the Cynips appeared; the 
rest gave the following results :—sixteen galls produced only 
Synergus melanopus; two, S. melanopus and a Eurytoma; 
twenty-eight, only, S. Hayneanus; five, S. Hayneanus, with . 
S. melanopus; two, only S. pallidipennis; three, 8S. palli- 
cornis; one, S. pallicornis and 8. melanopus; one, S. vul- 
garis; two, the Cynips and S. melanopus; one large gall 
produced the Cynips, seven examples of 8. melanopus, and 
one Eurytoma; four, the Cynips and S. pallicornis; and 
lastly, two, a Pteromalus. In the galls from which the 
Cynips and the Synergus appeared the cell of the first was 
quite closed and normally formed, but the cells of the lodgers 
were separate in the parenchyma. He mentions a gall of 
C. cerricola, which afforded him in April nineteen examples 
of S. thaumacera, and in May two of 8S. variabilis and three of 
Eurytoma: these all came from one hole, the passage to 
which was divided, and led from many chambers. It thus 
seems that in general the contrivances of the lodgers cause 
the death of the proprietor, for in sixty galls seven produced 
the Cynips and the Synergus ; the latter only or the parasite 
proceeded from the rest, and the imprisonment of the Cynips 
by the Synergus was first observed by Spinola. Life in these 
kinds of galls may be divided into two parts,—the inner life 
and the outer life,—the first represented by the Cynips and 
its parasites, the latter by the Synergus and its attendants; 
and the multiplying of the Cynips is not only limited by its 
parasites, but by the Synergi in the outer life; and in case 
the latter are the victims of other parasites, their habitations 
are not the less obstacles to the emergence of the Cynips; 
and the complications of life-forms in a gall are a little 
epitome of biology generally, with regard to insects. Dr. Mayr 
observes on the strangeness of the fact, and of its being 
worthy of close study, that a Synergus lives in one kind of 
gall three to four months, but in another kind a year or 
more. The species which appear in winter are more nume- 
rous than those which appear in summer, and those which are 
