DEVELOPMENT OF SPONGES FROM DISSOCIATED TISSUE CELLS. 1 3 



were kept in the laboratory one day longer. They remained unchanged and were then 

 discarded. 



Experiment record, August 22, 1907. — Specimen from Gallant's Point wharf was 

 cut up and pieces strained as above. The tissue was treated in the same way. The 

 cells and cell masses carried out the preliminary steps in the fusion process, but the 

 tissue soon began to die. 



STYLOTELLA HELIOPHILA. New Species. 

 DESCRIPTION OF SPECIES. 



This Stylotella is the most abundant sponge in Beaufort Harbor. Common on the bottom in shal- 

 low water attached to shells, also under wharves attached to piles, stones, etc. Habitus varies. 

 Sponge incrusts the shell or other substratum and grows up in shape of lobes. These may be quite 

 independent of one another. More commonly the ascending lobes fuse where they touch, and thus a 

 more compact mass is produced reaching but rarely exceeding 100 mm. in diameter, in which the original 

 lobes remain conspicuous. The oscula are for the most part at the ends of the lobes or at the ends of 

 tapering more or less conical outgrowths from the lobes. Pores scattered over dermal membrane. Sur- 

 face is diversified in appearance, owing to the canals which course in the ectosome, and is very generally 

 roughened with minute conulose elevations J^ to i mm. high. Color, orange, sometimes with a greenish 

 cast. 



The only spicule in the sponge is a smooth, style 120-350/1 by 4-8/1. Spicules of interior are 

 scattered irregularly. The arrangement may in places approach the condition of a reticulum, or the 

 spicules may combine to form vague spiculo-fibers or tracts. Spongin seems to be entirely absent. 



At the surface are abundant more or less radially arranged stales, some of them slightly projecting, 

 in places combined to form vague tufts. In some regions the ectosomal styles are about horizontal, 

 often forming loose tracts which fray out in a brush-like fashion at the end. 



FORMATION OF PLASMODIA. 



The following experiments show that I lie dissociated cells of Stylotella will unite 

 to form plasmodial masses. The behavior of the tissue is slow and feeble as compared 

 with Microciotia. In the actual experiments the plasmodial masses did not transform. 

 The tissue is certainly not hardy and dies easily. Possibly it needs the better aeration of 

 the outside water. The syncytial masses produced during the gradual degeneration 

 of this species in aquaria" have never transformed for me in laboratory aquaria, but 

 have transformed into functional sponges when removed to the harbor. 



Experiment record, August 9, 1907. — Specimen of Stylotella kept one day in aquar- 

 ium was cut into pieces, and the pieces strained in the usual way into large watch glasses. 

 The dissociated cells settle on the bottom and are strewn with pipette over cover glasses. 

 The tissue behaves in essentially the same way as the Microciona and Lissodcndoryx 

 tissue. Small masses are quickly formed, and these establish connection with one 

 another, thus producing fine plasmodial networks. Part of a cover-glass preparation 

 showing such a network is represented in figure 33. The cords of the network have a 

 dense syncytial structure and are J to J mm. wide. 



A number of such cover-glass preparations were made and kept in laboratory dishes. 

 On some covers the plasmodial networks remained unchanged and after a day or two 



o Wilson. H. v.: A new method by which sponges may be artificially reared. Science, n. s.. vol. XXV. no. 649, 1907. 

 85079° — Bull. 30 — 12 2 



