542 JOURNAL OF SCIENCE. 
the order, and the hyperparasite oviposits in one, or perhaps. occa- 
sionally more, of these; the dipterous maggots then eat their, way 
into the caterpillar, both insects afterwards developing, as we haye 
seen above.* 
This theory may of course be upset at any time by the discovery 
of the actual method; but, with the facts at present at my disposal, IT 
think the above is the most feasible explanation, and moreover, that it 
is not without a parallel in the insect world anyone will admit, who 
is acquainted with the life-history of the genus Sitaris among the 
Coleoptera. 
Karori, Wellington, New Zealand, 
March 25th, 1885. 
SOILS AND. HEALTH. 
(This article and the two which follow it are taken from ‘‘ Science” of July 10, 
1885, the ‘‘ Sanitary number.”) 
a 
The soil, especially the first few inches or feet below the surface, 
is the ante-chamber of life,—the laboratory in which operate inces- 
santly the processes by which inert matter is prepared for the 
nourishment of life. It is this, because it is also the tomb of all 
terrestrial living matter. Here is the realization of the Phcnix-myth; 
the slow combustion of organic matter leaving a residuum, from which 
springs the new life of succeeding generations. | 
These processes of the transformation of matter are the work of 
the low forms of microscopic life which are known as bacteria, and 
are gifted with the capacity of enormous and immensely rapid multi- 
plication. This world of microscopical life is vast as regards the 
distribution and number of its living entities. These minute 
organisms are known to be intimately connected with many of the 
fundamental processes of the organic world, and our knowledge of 
their range of activity is constantly increasing. 
They may be considered practically to stand in close genetic 
relations to many diseases; but the question of absolute differentiation 
of forms with specific functions, or of the possibility of Protean 
functional characteristics among them, varying with their surround. 
ings, is one of the present great problems of biology. 
* Sir Sidney Saunders met with a similar difficulty in the case of a Chalcis 
hyperparasite on a Sarcophaga living within the body of a locust (Wdipoda cruciata, 
Charp.) He says, ‘‘Hence the question arises, how the parent Chalcis obtained 
access to the Sarcophaga larve for the purpose of depositing her eggs? It might be 
supposed that this opportunity was afforded at the time when the adult larva quits 
the body of the locust to undergo its final metamorphoses in the earth. But such 
could not have been the case in this instance, when the transition took place witbin 
a closed box remote from their accustomed haunts. The egg must therefore have 
been deposited at an antecedent period, either while the larva was within the body 
of the locust, or probably still earlier, when the newly hatched larva was about to 
penetrate into the body of the locust.” (Proc. Ent. Soc. Lond., 1881, p. xxv.) 
’ 
i i 
——— eC 
