5Q2 Philippine Journal of Science *» 



cells, of which twelve with diameters of about 29 p. are darker 

 and thin walled, and sixteen with diameters of about 34 p are 

 lighter in color (they appear to have taken up some Bismarck 

 brown but no nigrosin) and enveloped with walls which vary 

 in thickness and in closeness of fit, the thicker ones fitting their 

 protoplasts more loosely, and all having reticulations developed 

 as ridges. One thin-walled reproductive cell on the far side 

 of the coenobium is smaller, about 25 p, and lighter colored 

 than the others, and may possibly be an endophyte. The coeno- 

 bium measured about 250 by 275 p when it was photographed 

 and now is 230 by 255 /«,. The somatic protoplasts have diam- 

 eters of about 4 to 5 /n and are in the outer rounded ends of 

 their prismatic membranes. The average cell diameter is about 

 9.4 p.. The estimated number of somatic cells is 2,300. That 

 this coenobium is younger than the one shown in Plate I, fig. 

 6, is evident, not only from the larger proportion of oogonia to 

 oospores, but from the incomplete development of the oospore 

 walls. The large number of relatively less-mature endophytic 

 algae also marks this coenobium as younger than the other. 

 The reproductive cells are absent about the anterior pole, and to 

 a lesser extent about the posterior pole, though the latter point 

 is more evident in the present position of the coenobium than 

 in that which it occupied at the time when the photograph was 

 taken. The radial dimensions of the somatic-cell membranes 

 does not reach the size of those in the preceding specimen. 



Notes on the four other specimens of sexual coenobia on the 

 type slide, taken in June, 1919, follow : 



Specimen 15. — Coenobium ovoid, 235 by 245 ¥■. Anterior end larger. 

 Somatic prisms about 20 ,u radial dimension about tbe anterior pole. 

 Oogonia, 28; 39 m, with central nucleus; a zone of dark bodies, possibly 

 chromatophores, about one-fourth or one-fifth radius from the periphery 

 and one-half or three-fifths radius from the center of the protoplast. 



Specimen 1 6. -—Coenobium, 210 by 270 a. Somatic protoplasts, about 

 5 m. Average cell diameter, about 10 m. Estimate of somatic cells 1,920. 

 Reproductive cells, 23. Oogonia, 16; 30 to 35 n. Oospores, 7; protoplasts, 

 about 32 a, walls about 40 a*. Each oogonium has a central nucleus and 

 dark bodies in the outer half of the radius. The oospores have a small 

 central nucleus or nucleolus. Two have walls almost smooth. The pro- 

 toplasts are eccentric. Three oogonia and one oospore appear more or 

 less disorganized and are surrounded by fungus hyphae. 



Specimen 1 7.— Coenobium, 260 by 295 m. Cells, about 2,330. Reproduc- 

 tive cells, 25. Oogonia, 2; 32 and 35 m. Oospores, 23; grading from dark 

 to light, 19 being darker and 4 lighter, the latter nearer maturity. Ridges 

 on spores high. Most spores with nucleus eccentric, twice as far from 

 one side as from the opposite. 



