AT THE MICROSCOPE. 115 



the country. Sowerby describes and figures a third species, 

 Typha minor, as found in Britain. This it would be very inter- 

 esting to see — no matter, in a micro-scientific point of view, 

 whether " doubtfully British '"' or no. 



Head of Cockroach; Gizzard of Cockroach.— I place these 

 together as types of a most important class of slides — such, 

 namely, as illustrate well the structure of the common objects by 

 which we are surrounded. It is of far more essential importance 

 to us that we should be familiar with the objects connected with 

 our daily life, than with such as we may see but at rare intervals, 

 and comparatively few ever at all. The same watchful Providence 

 and the same beneficent design are exhibited in the homeliest as in 

 the rarest objects. And if we act " Her Majesty's Commis- 

 sioner on Education," to our consciences, how little is there we 

 know of even such things as the Lesser House-Fly, the Cock- 

 roach, or the Cricket ! Know^ that is, in the sense of real 

 insight into their life-history — from the egg to the grave — as com- 

 pared with what we might gain by a moderate exercise of pains 

 and thought. The lessons to be learnt from them are full of as 

 profound interest and true wisdom, as from any study that man 

 can pursue. What is the history, from the egg to maturity, of 

 this, that, and the other ? let us ask ourselves ; and when we 

 really do know all that is to be learnt by the microscope about 

 them, we shall have acquired powers of observation and reasoning, 

 and a mass of accurate facts, vrhich will astonish ourselves and 

 others as well, and be able to add largely to the stores of commu- 

 nicable knowledge to be found as yet only in books. 



To the Gizzard we must accord a unanimous welcome. It is 

 so interesting to see the mill of one of these atrociously voracious 

 creatures. And in its simplicity, it furnishes so good a key to the 

 more complicated forms met with in some others of the Insect 

 tribe. 



In preparing it, what do we find ? Why, there's first next the 

 mouth a capacious thin-walled bag, the Crop, destined principally 

 for the reception of food. And how large it is in the vegetable- 

 feeders, the earwig and the grasshopper to wit ! Then we come 

 to the Gizzard, which may be likened to a pudding-bag, of some- 

 what triangular outline (see PI. XIV., Fig. 8). a, End of Crop ; 

 b, Gizzard, in profile ; r, CEsophagus, hexagonal in section (see 

 Fig. 9), with six powerful teeth, the points towards the wide 

 receptive apex pointing inwards. Between each of these is a 

 tendon of a fan shape. These serve to give strength to the walls, 

 and pohits d'appui for circular bands of muscular fibre ; outside 

 these cross-muscles are longitudinal ones, very short and strong. 

 By their combined action the mill is set in motion and kept going 



