[27] See the Table. [28] In Cloëon. We now approach mandibulated orders, and we shall see the loss of mandibles in Phryganea and Ephemera, although apparently resulting naturally enough from their distance from the type Libellula, has yet another cause--the proximity of classes that have no mandibles: in the city-building Ants, the mandibles are very perfect, and, therefore, we may expect them, and we find them in the city-building Termites. The opinion of philosophers, such as the authors of the _Introduction to Entomology_, is always worth having, although I am doubtful of assertions about insects, when unconfirmed by thorough entomologists; and I believe as yet no entomologist is sufficiently acquainted with the real history of white ants, to decide positively as to their different stages of existence. The following quotation contains also a corroboration of the propriety of this approach:--"The white ants, though they belong to the Neuroptera order, borrow their instinct from the hymenopterous social tribes, and, in conjunction with the ants, (Formica,) connect the two orders. Their societies consist of five descriptions of individuals:--workers, or larvæ; nymphs, or pupæ; neuters, or soldiers; males and females."[29] The class Coleoptera now approaches the Neuroptera, and on each side the boundary we find larvæ digging pitfalls in the sand to catch their prey, and having tubular mandibles to extract its juices when caught. We find them spinning silken cocoons, in which they change into quiescent pupæ, incapable of taking nutriment; which may fairly be supposed a symptom of approach; but there is no insect whose imago I would venture to place on the circumference of the neuropterous circle at the point. [29] Introduction to Entomology, Vol. II. p. 32.