102 MR. NEWPORT ON THE HABITS OF MONODONTOMERUS. 



The importance of a thorough examination of these microscopic pests is at once evident, 

 in the fact that the type of the family to which the whole of them belong is the noisome 

 parasite of the human subject ; that another, as yet undetermined form of the same tribe, 

 is thought by some to be connected with one of the most fatal ailments of our frame, 

 dysentery ; that two distinct Sar copies yet undescribed affect the horse and sheep ; and that 

 even the common sparrow, and our little pet the canary, are infested by others of this class. 



When, therefore, we reflect on the ailments which these produce, and on the diminutive 

 size of the creature I have just characterized, and which in its effects are so destructive 

 to other tribes, and bear in mind that this mere speck, this particle of dust, is organized 

 for all its purposes as completely as the most perfect of any of the whole sub-kingdom to 

 which it belongs, — even to the flexor, the extensor, and the rotator muscles of its truly 

 atomic limbs (fig. 9) and tarsi, — while the entire body of the creature, when first produced, 

 measures scarcely more than sixteen thousandths of an inch in length ; — and then call to 

 mind that the mere foot alone of the Dinomis, or of the JPalapteryx, the ancient colossal 

 birds of the Antipodes, measures, as shown by the most renowned anatomist of our age, 

 Professor Owen, more than twelve inches — nearly seven hundred and fifty times the whole 

 size of this little body : — who can but feel astonished at this range of Creation ? — who can 

 but feel that the study of natural history, — not as the amusement of an hour, but as a 

 sober contemplation, — must tend to exalt as well as to expand the human intellect ; and 

 that the most microscopic atom of organized life, considered as part of the world, is as 

 deserving of our fullest attention as the most gigantic ? 



DESCRIPTION OP THE PLATE. 



Tab. X. 



Fig. 1. A cell containing the larva of Anthophora attacked by larvae of Monodontomerus. (a) natural size ; 



(b) magnified two diameters. 

 Fig. 2. A cell containing the nymph of Anthophora attacked by the parasites : — magnified. 

 Fig. 3. Further details of the anatomy of Monodontomerus. Digestive system of the larva, (a) salivary 



organs ; (b) section of the oesophagus, (c) of the stomach, and {d) of the pylorus ; (e) the Mal- 



pighian vessels. 

 Fig. 4. Digestive system of the nymph, (a, b, c & d) oesophagus and stomach, as above ; (e) Malpighian 



vessels, exhibiting their cellaeform structure and mode of termination. 

 Fig. 5. Larva o{ Monodontomerus attacked by parasitic Acari. (a) natural size; (b) magnified three diameters. 

 Fig. 6. Newly developed adult Acarus, Heteropus ventricosus : — magnified. 

 Fig. 7- Pregnant female Heteropus ventricosus during the development of her ova : — magnified. 

 Fig. 8. Several fully developed Acari attached to part of the proboscis of the nymph of Anthophora. 

 Fig. 9. Posterior leg of the Acarus : — magnified. 

 Fig. 10. Magnified view of the head of the male Anthophorabia fasciata, Newp., as seen by transmitted 



light, exhibiting the structure of the antenna? (a), showing the flexor (1) and extensor (2) muscles, 



and (3) the cellaeform structure in the cavity of the basilar joint ; (b) the lateral, and (c) the 



vertical ocelli ; (d) the brain ; (e) the labrum ; (/) the mandibles. 



