On the Nauplius Sta^e of Prawns. 79 



IX. — On the Nauplius Stage of Prawns. 

 By C. Spence Bate, F.K.S. 



It is now fifteen years since Fritz Miiller published his memoir 

 " Die Verwandlung der Garneelen," in the Archiv f. Naturg. 

 1863. In this he announced that he had discovered that the 

 prawns, more especially mentioning Penceus, commenced life 

 in a stage closely approximating to that in which the Cirri- 

 pedes and some entomostracous Crustacea did, in that which 

 is now known as the Naupliits form. Fritz Miiller's high repu- 

 tation as an accurate observer and philosophic naturalist 

 induced carcinologists to accept his statement, although, as I 

 stated when reporting on his memoir in the * Zoological 

 Record ' for 1864, " in the chain there are one or two links 

 wanting to make the connexion perfect," adding, in a note, 

 that " since this passage has been in type. Dr. Miiller in- 

 forms us that the several links in the progressive develop- 

 ment have been established by him, closer than, for want of 

 space, he has been able to demonstrate in his work;" and I 

 further added, at page 283 of the same ' Record,' " The diffi- 

 culty of preserving the life of these delicate creatures has not 

 yet been overcome. The newly hatched larva from the com- 

 monest and, we might assume, the hardiest crabs has not been 



preserved beyond the second stage It is therefore 



not to be demanded that Dr. Miiller should succeed beyond 

 the step at which others have stopped. It is only necessary 

 for him to show assimilation of conditions to enable us to 

 accept his conclusions." 



Knowing that Captain Du Cane had, as far back as 1839, 

 published, in the second volume of the ' Annals and Magazine 

 of Natural History,' p. 168, pis. vi. & vii., the character and 

 form of the young of Palcemony and having also myself ob- 

 served that the prawns on our coast, as far as I had examined 

 them, exhibited no such character of metamorphosis, I, during 

 my correspondence with Fritz Miiller, suggested that the im- 

 portant link wanting was the connexion of the Naiiplius with 

 the parent, not, as he says, " the relation of the Nauplius 

 with the Zoea,'''' and that until this was done the chain 

 of evidence was not sufficient to compel acceptance, in the full 

 sense that he proposed, of the opinion '' that the Nauplius stage 

 was the earliest form of the larval condition of prawns ;" for, 

 as he remarks in the paper translated in the 'Annals ' for last 

 month, his Nauplius, having been taken swimming freely in 

 the sea, may not be the larva of Penceus at all. 



In the important advance which the study of the Crustacea 

 has of late taken, it is highly necessary that statements 



