430 Chronicles of Science. [July, 
The extraordinary sexual history of the spiders may account for this 
on Mr. Darwin’s principle of sexual selection. Thus the smaller the 
male individuals, the more chance they would have of escaping the 
ferocity of the female by playing at hide and seek among her limbs 
and over her body in the mode M. Vinson describes. This selection 
would go on exercising its inevitable influence upon the size of the 
males until at length they became what in M. Vinson’s instances they 
appear to be—mere parasites upon the female; the indefinite dimi- 
nution of the male would only be checked by the natural require- 
ment of a certain size for the fulfilment of the offices of impregnation. 
Lithodomous Annelids—Mr. Ray Lankester records some cases 
of Annelids of the genera Sabella and Leucodore which occurred in 
calcareous boulders, and points out the curious fact that none of the 
accompanying sand-stones, however indurated, nor the clay, were 
ever bored, the perforations being entirely confined to rocks of the 
same chemical composition, whether soft as chalk or dense as lime- 
stone. Having pointed out that there is no hard structure in these 
annelids which non-boring species do not possess, he concludes that 
the constant apposition of the tail of the annelid is the cause—and 
this is proved to be acid, for placed on blue litmus paper it gives a 
strong acid reaction in both species. It is not contended, however, 
that all cases of boring are due to chemical agency, for some, as the 
Pholas in gneiss, disprove the universality of this explanation. 
Pearl Fishing.—Australian letters relate a discovery of consi- 
derable importance, viz. the existence of an extensive pearl-fishery 
on the north-west coast of Western Australia. The fishing-ground 
is described as stretching along the coast no less than a thousand 
miles. There had been upwards of sixty tons of pearls obtained up 
to December, and these were purchased on the spot at the rate of 
1002. per ton. The banks at Perth will advance 100/. per ton, not 
including the inside pearls, which are valued at from 10. to 200. 
sterling each. About thirty men were then engaged in pearling. 
Swarms of Locusts.—Fearful devastation has been caused in 
Algeria by millions of locusts, which in the latter days of April 
last darkened the air for hours together, destroying every green 
thing. The inhabitants by every means in their power endeavoured 
to divert them from their fields, and torrents of rain drowned 
myriads of them, besides those killed by boys; but the destroyed 
numbers were but as a drop in the bucket to those which remained. 
Sickness was expected to follow this plague from the abundance of 
their putrefying bodies. 
Breeding of Queen Bees—M. De Romestin, English chaplain 
at Baden, calls the attention of English bee-keepers to a most 
important discovery made by M. Kohler, a Protestant minister in 
Hesse. It is no less than the secret of directing the breeding of the 
bee, so that, as with our cattle, we may select the choicest male to 
