498 W. WOODLAND. 



Part 2. — The Spicules of the Auricularia Larva. 



Introductory. 



The morphogenesis of the Auricularian wheel-spicule has 

 been described and figured by Senion (5). An nnillustrated 

 account of the scleroblastic development of the Auricularian 

 wheel has also been published by Chun (1) in 1892^ but, as I 

 surmised in Study IV, Chuu's remarkable statements con- 

 cerning this subject are totally misleading, owing to the fact 

 that he unconsciously studied decalcified material. As will 

 be seen in the quotation given below, Chun described the 

 spicule as being deposited within a mould which is formed 

 for its reception, so to speak, in the substance of the sclero- 

 plasm. I am able to say that this supposed mould is noth- 

 ing but the space contained within the scleroplasm which 

 was occupied by the spicule before it was dissolved away bj^ 

 acid reagents. I have recently observed many of these 

 ^'moulds" in improperly preserved (decalcified) material, and 

 I am able to make the above statement concerning their real 

 nature because I also possess properly preserved (undecal- 

 cified) material. 



My material consisted of numerous Auricularia larvae in 

 different stages of growth obtained at Naples and specially 

 fixed with absolute alcohol. I stained them for a week in a 

 saturated solution of Griibler's safranin in absolute alcohol, 

 and washed out the superfluous stain by keeping the larvfc 

 in warm 90 per cent. alcohoP (several changes) for a week ; 

 they were then dehydrated, cleared in cedar-wood oil and 

 mounted in balsam in the ordinary way. 



The Develoi'ment or the Spicules of the Auricularia 



Larva. 



The wheels and " globes," as I shall term the other class of 

 calcareous deposits found in the Auricularia larva, are found 



' Absolute alcoiiol with the required percentage of distilled water to ensure 

 neutrality. 



