()7i (lie Development o/ t/ic ('rustucedu Ftnhriji'. 1 7o 



the parents from which they had Ijcoii dlitaiiifd ; in relation to 

 whidi Mr. I'owt'r wrote: — 



*' Dkau >Siu, — I have to thank you for your kindness in answering 

 my letter to Dr. Carpentvr, and for the memoirs. 



*' My fol lection of Crustacea and the microscope-slides of the 

 larva; are at present, and have heen, pa<*ked up in Fort Louis. 

 Now 1 am a<;ain on detachment ; and if left here in peace for a 

 few months, I shall arnuige uiy specimens. and tiuish up the micro- 

 scopic drawings. 



"All my larvie are hatched in basins (the only kind of aquaria 

 my nomad life allows me to use); so each crab or prawn &e. whose 

 larvie I possess is ideiitilied with its younjjj. Ajid this reminds me 

 that on reading Fritz Midler's jjaper in the 'Annals' (lS<i4, vol. 

 xiv. p. lo4), I was much astoinshed, as none of the prawns or 

 prawn-allies whose young 1 have hatched show any such yau^lius 

 form as sho\Mi in figures 1 <.t 3, «fec., but all 1 have observed a.s 

 yet are born like fig. S, or near it. 



" 1 have been quite unable to rear any crab-larvae beyond a day 

 or two after birth ; whether they require moving water or not I do 

 not know ; but certainly, though 1 have kept the parents alive for 

 several weeks in basins (the water changed once or twice in 24 

 hours) of salt water, the same method would not succeed with 

 the larva*. I then tried small ai|uaria, and signally failed again. 



" I have not been in the neighbourhood of fresh water as yet, so 

 have had no opportunities of observing the freshwater Crustacea, 

 though there are a good many crab and shrimp forms. I have 

 found two kinds of that curious parasitic crustacean which adheres 

 like a little polypus, a mere bag with a peduncle, but containing 

 hundreds of young Crustacea whose genus 1 do not know, as i 

 cannot find any account of them in Van der Hoeven's ' Zoolog}' '*. 



" If I succeed in getting posted to one of the regiments here, 

 my life \\i\\ be more stationary, and I shall have far lietter chances 

 of working my crab-hatchings. 



'• In Fritz Miiller's paper before referred to, I fancy that he has 

 not hatched the different larvje mentioned. After reading the 

 paper very carefully, 1 could not help fancying that the various 

 stages of development were not hatched through, but specimens 

 were captured at different times, and perhaps larva; of totally diffe- 

 rent species have been given as stages of the same animal. 1 say 

 this with great doubt ; but reading the paper will, 1 think, bring 

 everyone to the same conclusion. Thus he says, 'the unaltered 

 Nmtplin.^ form, probably the same in which the animal escapes from 

 the egg, came under notice only once ;" again, ' This larva (taken 

 on the Kith of January) is closely approached by four others, 

 probably hflonijitui to the same swarm, which were taken at the 

 same time (li4th January);' and so on. 



" To tow a net in these tropical seas and to examine all the 

 microscopic CVustact^ would give a most extraordinary assemblage 



[• New genus alliwl to Sarnilina, which hntoli larv«p in the rirriprd pujiii 

 •Uge.-C. S. B] 



