142 KANSAS ACADE3IY OF SCIENCE. 



step in the elimination of a polar globule or its functional equivalent, liquid or solid, I 

 cannot say, as I was unable to pursue the investigation further at that time. But until 

 farther study of the fate of the germative vesicle can be made, I hold the provisional 

 opinion that this migration and protrusion, taken in connection with the condition of the 

 germative vesicle in this and other ova simultaneously taken from the same ovary and 

 treated with picro-carmine, represented an initial phase of such an elimination. 



The germinative vesicle of the particular ovum concerned in the above-mentioned 

 protuberance had, at the time of that protuberance, one large and several accessory nucle- 

 oli, of which the former, at least, had one large vacuole. 



The following is an account of the general appearance presented by the germinative 

 vesicle in this and other ova of the same brood, the growth of all of which must have 

 been arrested at nearly the same stage of development : It possessed a distinct but thin, 

 transparent and flaccid limiting membrane. Visible beneath this membrane was a broad- 

 meshed, but most delicate, lattice, composed of exceedingly fine granules — much finer 

 than those in the protoplasm of the general egg body — and appearing much like a 

 dissolving remnant of the intranuclear trestle*. There were in each instance, besides 

 the large nucleolus, several, sometimes upwards of thirty, accessory nucleoli. There 

 was a marked relation between the number of these accessory nucleoli and their size. 

 When numerous, they were all small ; when few, two or three of them, at least, were 

 relatively large. Both principal and accessory nucleoli were vacuolated. In a germ- 

 inative vesicle with but eight accessory nucleoli, the principal nucleolus had one large 

 vacuole of subangular outline, about which were other and minute vacuoles. In those 

 with numerous accessory nucleoli, the vacuole had become so extremely large that the 

 solid part was reduced to a spherical shell, converting the nucleolus into a mere vesicle, 

 its wall, however, still much thicker than that of the germinative vesicle itself. 



As migration of the germinative vesicle to the periphery of the ovum is a constant 

 and indeed necessary step in the elimination of polar globules or their potential equiv- 

 alents, and as this migration is universally accompanied by metamorphosis of the germi- 

 native vesicle, more or less distinctively retrogressive ; and particularly in view of the 

 researches of Van Beneden and Fol, who have shown that in the ovum of Asteraeanthion 

 the formation of nucleolar vacuoles and accessory nucleoli are phenomena characteristic 

 of such retrogression, I regard it as probable that the migration and metamorphic ap- 

 pearances above noted indicate the ultimate partial elimination of the germinative 

 vesicle in Porcellio. 



I am by no means confident that the extreme aspect of the vacuolation which I have 

 recorded was not an effect of the staining-reagent; but thus to explain the concomitant 

 phenomena, is hardly possible, and the most reasonable conclusion seems, therefore, to be 

 that to which I have already pointed, a conclusion which, I must humbly confess, lacks 

 that most desirable element in scientific deductions — certainty. It is, then, with the 

 hope that this conclusion may ere long be either verified or refuted by new experimental 

 evidence, that it is here presented. 



BOTANICAL ADDENDA FOB THE YEABS 1883 AND 1884. 



BY PROF. J. H. CARRTJTH, LAWRENCE. 



The work of making a catalogue of the plants of Kansas is so nearly completed, and 

 my salary as a State officer is so very meager, that I have done but little myself. I have 

 found one plant, and two have come up in my garden. Mr. E. Bartholomew, of Bock- 



s This trestle, or network, is a well-defined structure in the earlier history of the ovarian egg of 

 Porcellio. 



