On the Interjjretation of the Sponge Organism. 399 



the discocelliilar veinlet. The Euptevotidte moreover can at 

 once be distinguished from the Lasiocampida3 by the 

 important character of their well-developed frenulum, this 

 being entirely absent in the Lasiocampidas. The larvae of the 

 LasiocampidsB are densely hairy, often with long thick tufts 

 directed forwards on either side of the head, or backwards from 

 the anal segment, as in the Liparidte (to which Mr. Hampson 

 considers them allied) ; whereas the larvteof the Eupterotida3 

 are more Arctiid in character, such hairs as there are, whether 

 few or many, being chiefly emitted in tufts from wart-like 

 excrescences. 



There can be no doubt whatever, from the entire structure 

 of the moths and the character of their larv^, that Anaphe 

 and Hypsoides must be placed in the family Eupterotida3 of 

 Hampson. 



XLV, — The Interpretation of the Sponge Organism^ and some 

 Recent Works on Sponges. By i)r. Otto Maas *. 



Since the investigations of F. E. Schulze on the structure 

 and development of sponges paved tlie way, probably all 

 zoologists have looked upon these animals as three-lagered, 

 consisting of an outer and an inner layer of epithelium, and 

 enclosed by these a connective-tissue mass with cells and 

 deposits of various kinds. This method of interpretation 

 does not take into consideration the question whether the 

 three layers correspond to the layers which arise from ecto- 

 derm, endoderm, and mesoderm in higher animals, and also 

 does not necessitate our holding any particular view regarding 

 the systematic position of sponges. As a matter of fact the 

 adherents of the most divergent theories on this point — 

 both those who derive sponges from a special class of Protozoa 

 separated from other Metazoa, and those who consider them 

 as true Metazoa, but as a special phylum, as well as, finally, 

 those by whom sponges are regarded only as a degenerate 

 branch of the Coelenterate stem — have all recognized the 

 three-layered structure of sponges in their speculations. 



Another question specially referring to the group of sponges 

 would be whether the three layers of the adult arise in 

 the development of the individual sponge from three separate 



* Translated from a separate impression, communicated by the Author, 

 from the ' Biologischos Centralblatt,' Bd. xii. nos. 18-19, pp. .5GG-o72 

 (Oct. 181)2). 



