219 



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

 2 prosopyles, 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 

 which 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-diagrammatic). 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. I. 

 = choanocytic layer; mesgl. = mesogloea; am. = 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. I.) into a parenchymal tissue-bridge (semi-diagrammatic). 

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

 and moved on (1 — 2 — 3—4—5)., in III grain b. ejected and moved 

 on (1-2-3-4-5—6-7). See p. 147. 



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

 the mesogloea into the amoebocytes. ea. =z 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 undifferentiated flowing plasma (pi. I.) 

 situated outside and against the base of the choanocytes (ch. I.)- 

 an oildrop is moved on slowly (1—2—3). See p. 151—154. * 



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

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

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

 (ch. I.) has been drawn as one whole; it lodges numerous captured 

 carmine particles. Similar particles are carried along in the plasmic 

 layer (1 — 2—3) to a deposit place, from where now and then a 

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

 p. 151—154, 160—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— 6- c) and in the „bridge" (i— 2— 5—4— 5). c/(. /. = choa- 

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

 has been captured. See p. 151 — 154. 



Fig. 75. The captui-e (t?) and the carrying aside (3—4) of a coarse (food-) 

 particle, that i-eniained sticking in the prosopyle (i— 2), by means 

 of the layer of flowing protoplasm (pi. I.). 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 captui-ed. Magnif. ± 1000 times. See p. 152. 



