XXlil 
Prof. Westwood directed attention to a paper by Mr. Packard, just published in 
|} the ‘Annals and Magazine of Natural History, in which it was asserted that the 
| pup of Hymenoptera go through a series of mutations of form, analugous to those of 
| Chloeon, as detailed by Sir John Lubbock. He suggested that the hive-bee afforded 
| a good subject for observations in corroboration of this theory. 
Mr. M‘Lachlan mentioned the capture, on the banks of the Mole, near Reigate, of 
| Sisyra Dalii (Hemerobiide), on the occasion of the Society’s excursion thither, on the 
| 6th ultimo; and exhibited a collection of cases of caddis-worms, part of which were 
| from Bavaria, and the rest bad been collected by Mr, Albert Miiller in the neighbour- 
hood of Basle. Amongst them were some remarkable forms of the case of Halesus 
digitatus, the case (formed of sand) of Enoicyla pusilla, of which the larva is non- 
| aquatic, and a singular case, of uncertain genus, formed of vegetable matter arranged 
| transversely so as to form a partially angular tube closed by a solid operculum, in the 
| centre of which were four small holes to admit the water. 
| The Secretary read a communication respecting the recent plague of locusts in 
| Algeria, the serious character of which was confirmed by an official circular issued by 
| Marshal Canrobert. The creatures first appeared during the month of April; coming 
| from the gorges of the mountains and the fertile valleys of the littoral, they descended 
first on the plain of the Mitidja and the Sahel of Algiers. Their mass, at certain 
| points, intercepted the light of the sun, and produced an effect similar to that of the 
| snow storms which, in the winter season, fall in Europe, and blot out even the nearest 
_ objects from the sight. The vegetation of the country offered an attractive bait to the 
destructive insects. A large portion of the colza, oat, late barley and vegetable crops 
| were immediately destroyed, and in some parts even the interiors of houses were 
invaded. The Marshal used all his endeavours in encouraging the population in 
their efforts against the invaders; by his orders the troops were called out tu help the 
colonists to combat the plague, and the Arabs, whose interests were also at stake, 
joined their efforts against the common enemy. In a few days enormous quantities of 
_ the insects were destroyed; but human efforts had little effect against those winged 
multitudes, which fled over the country, and only abandoned one field to fall upon 
another. It was impossible to prevent fecundation and the deposit of eggs, which 
quickly gave life to larve innumerable, so that the first swarms were soon replaced and 
centupled by new generations. The appearance of these young locusts is especially to 
be dreaded, on account of their voracity ; the hungry myriads fell upon everything 
which had escaped the depredations of their predecessors. They filled up the water- 
courses, the canals, and the rivulets, and the troops had the greatest difficulty in 
preserving the water from infection. Almost at the same time the provinces of Oran 
and Constantine were invaded. At Tlemcen, where no locusts had appeared within 
the memory of the oldest inhabitants, the soil was covered with them. At Sidi-bel- 
Abbés, at Sidi-Brahim, and at Mostaganem, they attacked not only the tobacco planta- 
tions, the vines, and the fig trees, but also the olive trees, notwithstanding the bitter- 
ness of the leaves of the latter, At Relizabe and at Harba they invaded the cotton 
grounds. The road between Mostaganem and Mascara was literally covered with 
them along its entire course of fifty miles. In the province of Constantine the locusts 
appeared simultaneously from the Sahara to the sea, and from Bougie to Calle. At 
Batna, at Selif, at Constantine, at Gelma, at Boue, at Philippeville, and at Djidjelly, 
the people acted energetically against the invasion, but neither fire nor other obstacles 
