496 Philippine Journal of Science w* 



and about 5 p in diameter. They lack protoplasmic connections 

 with their neighbors. They number about 2,830. The distance 

 between neighboring protoplasts is about equal to the diameters 

 of the protoplasts. In surface view a rather thick middle 

 lamella, more, deeply stained with Bismarck brown, is visible. 

 In profile view the walls of all the somatic cells are seen to be 

 rounded on the outer side, making the surface of the coenobium 

 uneven. The inner membranes do not show plainly. 



The specimen contains three gonidia, and four embryos which 

 were formed from gonidia. Two embryos in the posterior part 

 of the coenobium are in the same stage of development, and two 

 embryos about in the equatorial plane are nearly in the same 

 less-advanced stage of development. The three gonidia lie just 

 in advance of the equatorial plane and are all mature and nearly 

 ready for segmentation. They measure in the photograph 47 

 and 52 n wide and are slightly flattened. Measurement of the 

 same gonidia in the preparation on June 9, 1919, gave the same 

 figures. Thus the gonidia show practically no shrinkage in 

 three years while the membranes shrank from 11 to 18 per cent 

 in dimensions during that time. The slight flatness of the 

 gonidia is taken to be the first indication of approaching seg- 

 mentation. The gonidia are highly vacuolate, with a centrally 

 suspended nucleus containing a well-marked nucleolus. The 

 membranes about each gonidium and about each embryo fit 

 rather closely. The equatorial embryos have reached the bowl 

 stage. Each bears eight gonidia on the edge of the bowl. The 

 size of these gonidia indicates that they were differentiated and 

 ceased to divide at about the 64-celled stage of the embryo. The 

 bowl has a somewhat dentate edge with the gonidia in the 

 points of the teeth. The somatic cells are very small, about 

 1 or 2 fi thick and 4 ^ long, and are numerous, about equal in 

 number to the somatic cells of the parent coenobium in the em- 

 bryo next to the single gonidium, somewhat larger and about 

 half as numerous in the embryo adjoining the pair of gonidia. 

 This appears to indicate that this embryo is at a stage just 

 preceding the last division of the somatic cells. Some marginal 

 cells of the bowl, between the daughter gonidia, seem to be about 

 twice as thick as the other somatogenic cells. This is sug- 

 gestive of marginal growth of the bowl. The posterior embryos 

 have reached the bullet stage. Their gonidia have entered by 

 the phialopore and the latter has closed. The gonidia are 

 packed too closely in the posterior part of the embryo to be 

 counted. 



