The most destructive of the _Blattæ_, or Cockroaches, are those which have been imported into Europe by the ships coming from the colonies. The _Kakerlac Americana_ is from an inch to an inch and a quarter long. It infests ships, running about at night over the sleeping passengers, and devouring the food. They are to be met with in all parts of the world. They abound particularly in the warm parts of America. The _Blatta orientalis_ is more commonly met with than the above. It swarms in kitchens, in bakers' shops, provision shops, &c., where it hides in the cracks of the walls, or against the hinges of the doors. It is a small hideous animal, of a repulsive smell, and of a reddish brown colour. It is a little larger than the _Blatta Americana_. In France it is called by various names, such as _Cafard_, _Panetière_, _Noirot_, _Bête noir_, &c. If in the middle of the night you suddenly enter with a light into the down-stairs kitchens, you will often see these little beasts running about on the table, and devouring the remains of the food with astonishing rapidity. The largest species of the genus of which we are now treating is the _Kakerlac insignis_, which inhabits Cayenne and Brazil, and in length sometimes exceeds an inch and three-quarters, and in the extent of its wings four inches and a half. It is principally in hot countries that the cockroaches do the greatest damage. In the Antilles, of which they are the pest, it is affirmed that in one single night they can bore holes through trunks, through cases, and through bags, and destroy objects which were supposed to be in perfect safety. Sometimes the walls, the floors, the beds, the tables, everything, in short, is infested by them, and it is impossible to find a way of preserving the food from their repulsive touch. One can, however, partially succeed in destroying them by the aid of insect powders. They have, however, natural enemies. Poultry and owls are very fond of them. A species of wasp, _Chlorion compressum_, lays up a stock of cockroaches, which it previously renders insensible, for its larvæ. Many species of _Chalcidiæ_, a family of Hymenoptera, also live on the eggs of these Orthoptera. There are also among the cockroaches certain brightly-coloured exotic species. These colours show that they do not avoid the light. We will mention as examples the _Brachycola robusta_ and the species of _Corydia_. The _Mantidæ_ are pretty insects, of very different habits from the preceding. They alone of the Orthoptera are carnivorous. They eat live insects, seizing their prey as it passes by them. They rest generally on shrubs, remaining for hours together perfectly motionless, the better to deceive other insects which are to become their victims.