219 



4 



Fig. 66. The capture of (food-)particles witliin a flagellated chamber with 

 2 pi'osopyles, viz. between the bases of the collars of the choano- 

 cytes (semi-diagrammatic). The way taken by the particles is 

 indicated by dots. Tlie separate cells of the choanacytic layer 

 (ch.l.) have not been drawn; the layer contains numerous particles 

 w'hich have been captured. Magnif. ± 1000 times. See p. 143 — 146. 



Figs. 67—68. The capture of a carmine grain between 3 collars (Fig. 67), 

 and the descending of the grain along a collar to the base (Fig. 

 68, 1 — 2) (semi-diagraminalic). See p. 145. 



Fig. 69. A flagellated chamber and its surroundings in a living green Spon- 

 gilla grown on coverglass (magnif. ± 800 times). gr. alg. = green 

 .,symbiotic" algae; cl. alg. = colourless „symbiotic" algae; ch. l. 

 = choanocytic layer; mesgl. = mesogloea; ai)i. = amoebocyte; 

 nu. = nucleus; vac. = food vacuole; odr. = oildrops. By 1 — 2 — 3 

 is represented the ejection of „symbiotic" algae by the choano- 

 cytic layer into the mesogloea. See p. 16, 147, 174. 



Fig. 70. Two carmine grains (a. and b.) ejected from a choanocytic layer 

 (ch. l.) into a parenchymal tissue-bridge (semi-diagrammatic). 

 In I the original condition is given; in II grain o. was ejected 

 and moved on (i — 2 — 3—4 — 5), in III grain h. ejected and moved 

 on {i— 2— 3-4-5— 6—1). See p. 147. 



Fig. 71. The spreading of carmine from a flagellated chamber through 

 the mesogloea into the amoebocytes. ca. = carmine grains and 

 conglomerates ; the other indications as in Fig. 69. Magnif. ± 800 

 times. See p. 147—148, 174. 



Fig. 72. The layer of apparently undiiferentiated flowing plasma {pi. l.) 

 situated outside and against the base of the choanocytes {ch. l.); 

 an oildrop is moved on slowly (i — 2—3). See p. 151 — 154. 



Fig. 73. Semi-diagrammatic representation of a flagellated chamber with 

 the layer of flowing protoplasm (pLl.) lying against the choano- 

 cytes at the side of the incurrent canal. The choanocytic layer 

 (ch. l.) has been drawn -as one vvhole; it lodges numerous captured 

 carmine particles. Similar particles are carried along in the plasmic 

 layer (i — 2 — 3) to a deposit place, from where now and then a 

 large (fecal) conglomerate is ejected. Magnif. + 1000 times. See 

 p. 151—154, 166—168. 



Fig. 74. Three flagellated chambers and incurrent canal {can.)\ layer of 

 flowing plasma against the base of the choanocytes at the side 

 of the canal; tissue ., bridge" bent through the canal (semi-diagram- 

 matic). The figure represents the transport of carmine in the plasmic 

 layer (a—fe-c) and in the „bridge" (/— 2— 3—4— .5). c/(. /. = choa- 

 nocytic layer; ca. = carmine (grains and conglomerates) which 

 has been captured. See p. 151 — 154. 



Fig. 75. The capture {2) and the carrying aside (3—4) of a coarse (food-) 

 partiele, that remained sticking in the prosopyle (1 — 2), by means 

 of the layer of flowing protoplasm (pi. l.). The figure is semi- 

 diagrammatic. The separate cells of the choanocytic layer (ch. l.) 

 have not been drawn; the layer contains numerous particles which 

 have been captured. Magnif. + 1000 times. See p. 152. 



