36 ARKIV FÖR ZOOLOGI. BAND 13. NIO 25- 



Explanation of plates.i 



Plate 1. 



Coelomic corpuscles of Labidoplax buslii. 



Fig. 1. — Twelve red amoebocytes with sperules (= kulamoebo- 

 cyter); their clear, homogeneous plasm presenting itself in different 

 positions; greatest lengtli =11,4 [J-; drawn from tlie living. 



Fig. 2. — Six hyaline, structureless, oval or fusiform corpuscles 

 (crystals?), varying in lengtli from 11,4 {J. to 30,4 [J.; drawn from the 

 living. 



Fig. 3. — A sample of a discoidal plasma-amoebocyte in want 

 of pseiidopodia, fixed 15 minutes af ter withdrawal of the coelomic 

 fluid; diameter = 30,6 [J-; nucleus == from 4,9 [J- to 5,i [J-; stained and 

 mounted in balsam. 



Fig. 4. - — ^ A plasma-amoebocyte with pseudopodia and vacuoles; 

 fixation occurred 1 hour and 15 minutes af ter withdrawal of coelomic 

 fluid; lengtli total = 51 ]}.; nucleus = 5, i [i; stained and mounted in 

 balsam. 



Fig. 5. — A commoii view of two plasma-amoebocytes united 

 by a long pseudopodial thread to a thin syncytium; fixed in Perényi's 

 fluid 1 hour and 15 minutes af ter withdrawal of the coelomic fluid, 

 stained and mounted in balsam; leiigth total = 85 [X. 



Fig. 6. — Another syncytium of two cells from the same j) repara- 

 tion; the combining pseudopodial thread has been cut off at x; lengtli 

 total = 68 \L. 



Plate 2. 



Coelomic corpuscles of Labidoplax buskii. 



Fig. 1. ^ — A syncytium formed by the fusion of three plasma- 

 amoebocytes; fixation occured 50 minutes af ter withdrawal of the 

 fluid;. lengtli total = 93,5 {J.; diameter of the nucleus = 5,1 [i; dia- 

 meter of the globular amoebocyte with sperules ==• 5,95 [J.. 



Fig. 2. — A i)lasma-amoebocyte from the same preparation; dia- 

 meter = 39 [J.; nucleus =6,8 {J-. 



Fig. 3. — A plasma-amoebocyte from the same preparation; lengtli 

 of the cell-body itself with its lower protrusion = 30,6 p^; length of the 

 upper pseudopodium, thought to be drawn out in a straight line = 

 68 \y.. 



' All the figures are drawn as seen imder a high magnifying power; 

 the natural size is stated in the text or in the explanation of plates. 



