Dr Goring and Mr Pritchard's Treatise on the Microscope. 361 



forward with the most sanguine expectations to the publication of the pre- 

 sent work. We knew well that both its authors were peculiarly fitted for 

 executing in a superior manner particular departments of such an exten- 

 sive undertaking ; but we were unable to anticipate how Dr Goring would 

 execiite the drawings of microscopic objects, or how Mr Pritchard would 

 discharge the functions of the naturalist. This information, however, is 

 amply supplied by the first number of the work ; and we have no hesita- 

 tion in stating it as our opmion, that Dr Goring and Mr Pritchard have both 

 accomplished these difficult tasks with the greatest success. 



The first number, now before us, commences with an exordium or pre- 

 face, written in Dr Goring's peculiar but forcible style, and vindicat- 

 ing microscopic science from the sarcasms of ignorant and presumptuous 

 pretenders. The first chapter, which is also from the pen of Dr Goring, 

 contains practical remarks on Microscopes for viewing and drawing Aquatic 

 LarvcBt S^c. The other two chapters of the number, which are written by Mr 

 Pritchard, are entitled, 1. On the Larva and Pupa of a straw-coloured plum- 

 ed Culex or Gnat ; and 2. On the Larva and Chrysalis of the Ephemera 

 marginalis. The coloured drawings by Dr Goring, by which these two 

 chapters are illustrated, are executed in such a masterly manner, that they 

 will themselves bear to be seen by the microscope, and they cannot fail to 

 impress the observer with the conviction, that they are correct portraits of 

 the living animals. 



The description of the larva and pupa of the plumed gnat will be interest- 

 ing to the naturalist. 



" The transformation," says Mr Pritchard, " of this animal from the larva 

 to the pupa is one of the most singular and wonderful changes that can be 

 conceived ; and under the microscope presents to the admirer of nature a 

 most curious and interesting spectacle. Although the whole operation is 

 under the immediate inspection of the observer, yet so complete is the 

 change, that its former organization can scarcely be recognized in its new 

 state of existence. 



" If we now compare the different parts of the larva with the pupa, we 

 remark a very striking change in the tail, which, in the previous state of 

 being, was composed of 22 beautifully plumed branches; while, in the 

 latter, it is converted into two fine membranous tissues ramified. This 

 change appears the more remarkable, as not the slightest resemblance can 

 be discovered between them ; nor can any vestiges of the former tail be 

 found in the water. The partial disappearance of the shell-like bodies is 

 another curious circumstance. The two lower of them, it may be conjec- 

 tured, go to form the new tail, for if the number of joints be counted from 

 the head, the new tail will be found appended to that joint which was 

 nearest them in the larva state. The two small horns which form the white 

 plumed antennai of this species of gnat, when in its perfect state, are dis- 

 cernible in the larva folded up under the skin near the head. The ali- 

 mentary canal appears nearly to vanish in the pupa, as in that state there 

 is no necessity for it, the insect then entirely abstaining from food ; while, 

 near this canal, the two intestinal blood-vessels seen in the larva hav^ 



