LARVAL FORMS OF THE CRUSTACEA. 175 



There now remains the question of their origin, and from 

 whence came the material from which they crystallised. My 

 theory is, that underneath the shale will be found a deposit of 

 coal, perhaps under the mine, certainly in its near neighbourhood, 

 (a rich coal stratum is now being worked, which crops up to the 

 surface in the Transvaal, about loo miles distant from Kimberley,) 

 and that subsequently to this carboniferous period the volcanoes 

 were in a state of activity, during which the carbonic-acid gas, 

 evolved from the coal in process of formation, found an outlet 

 into the pipe or crater of the volcano, entering it like a blast. 

 The gas would thus be in the presence of the natural forces 

 necessary to determine its crystalHsation, viz., pressure and heat. 

 The changes of temperature that the molten rock in the crater 

 would be subjected to accounts for the shattered condition the 

 Diamonds frequently present ; also for the irregularities of their 

 cr}^stallisation. Finally, the answer I would give to the question 

 of "What is the Diamond?" is that it is crystallised sunshine. 

 The solar rays absorbed by the vegetation of the coal-measures 

 now shine forth from these beautiful gems. 



®n tbc Stub^ of the Xarval fovnw 

 of tbc Cru0tacca^ 



By Edward Lovett, Croydon. 



THE early stages of the Crustacea are less known than are 

 those of any other order of animals ; for the insects of our 

 Islands have been so thoroughly worked, that even the 

 life -history of the Micro-lepidoptera have received elaborate 

 description. The Mollusca, too, are fairly well known as to their 

 reproduction, and so, too, are the fishes. Yet the Zooea, or 

 larval forms of many of our British Crustacea are apparently 

 unknown, and those even of less rare species are strangers to all 

 but those naturalists who have made these interesting creatures 

 their study. It is only within the last sixty or seventy years that 



