282 E. A. MINCHIN. 



nation were found to contain spores, sporoblasts, or (in one 

 instance) sporoblasts together with nucleated protoplasmic 

 masses of various sizes. Only in a single instance did I suc- 

 ceed in finding the adult Gregarine. In this instance the" 

 blood-vessels, which are of a rich brown colour, bore no vesi- 

 cles, but a few opaque white spots could be plainly observed 

 in the interior of the vessels, shining through the dark walls. 

 The walls of the vessels were not evaginated in any way, and 

 by gently pressing the wall of the vessels these white spots, 

 which were the adult Gregarines, could be made to shift their 

 position. By snipping the blood-vessel with scissors close to 

 the white spot and pressing it, the Gregarine was made to 

 emerge quite uninjured from the cut end. Examination with 

 the microscope showed an opaque white mass, appearing black 

 of course in transmitted light, quite motionless, of irregular 

 shape (fig. 1), and of such strange appearance that at first I 

 doubted if it was a Gregarine at all, the more so as even after 

 fixing and staining, and clearing the object in oil of cloves, I 

 could observe nothing of a nucleus or other structure, so 

 great was the opacity of the protoplasm. By careful search- 

 ing I found four more Gregarines, making five in all. Of 

 these five, two were stained and mounted whole in Canada 

 balsam, a third was teased up in order to try and find the 

 nucleus (this preparation proved, however, useless), while the 

 remaining two were carefully removed without disturbing 

 them in the blood-vessel, fixed with Kleinenberg's picric, and 

 cut into a series of sections. 



Fig. 1 shows one of these Gregarines drawn living when 

 freshly removed from the Holothurian. I have the same 

 specimen now mounted in Canada balsam, but it is so opaque 

 and granular that I can make out no more of the structure 

 than is shown in the figure j the nuclei, which were probably 

 faintly stained, escape observation even with the most careful 

 focussing. Fig. 2 represents another animal, drawn from a 

 Canada balsam preparation, in which eight faintly stained 

 nuclei can be plainly made out, and have been drawn with the 

 camera in their natural positions. In addition a faint but dis- 



