980 



SCIENCE 



[N. S. Vol. XXIX. No. 755 



into the cytoplasm, where they break up into 

 finely granular masses called yolk nuclei. The 

 yolk nuclei become more or less difiused 

 through the cytoplasm, and, especially toward 

 the egg membrane, give rise to the yolk 

 platelets, which are at first minute, but grow 

 during the winter to large size. Thus the 

 nucleo albumin of the yolk platelets is de- 

 rived from the nucleoproteids of the nucleus.* 

 Whereas I am entirely ignorant of the steps 

 by which a nucleoproteid might be changed 

 into a nucleoalbumin, the phosphorus content 

 of the egg nucleoalbumins (.4-1.5 per cent.) 

 is about the same as that of the native nucleo- 

 proteids studied by Halliburton.'' We might 

 compare the migrating nucleoli to the tropho- 

 chromatin of the protozoa and metazoa.° 

 Whereas the nucleolus is more acidophilous 

 to stains than the idiochromatin (chromo- 

 somes), it is more basiphilous than the gen- _ 

 eral cytoplasm, and I see no objection to call- 

 ing it trophochromatin. Goldschmidt* found 

 the chromidia (trophochromatin) of some pro- 

 tozoa to give rise to " glanzkorper " or glyco- 

 gen granules which might be compared in 

 function to the yolk platelets of the frog's egg. 



Whereas I found that the nucleoli were of 

 greater specific gravity than the nuclear sap, 

 and could be thrown out of the germinal ves- 

 icle by centrifugal force, there is no indica- 

 tion that gravity aids in the normal extrusion 

 of the nucleoli. Such migration of nucleoli 

 is a wide-spread phenomenon in animals and 

 plants." 



J. F. McClendon 



Univebsitt of Missouri, 

 May 15, 1909 



THE STRUCTURE OF LILY PISTILS 



In an extended study of the structure of 

 the pistils of Liliaeese some results have been 

 reached that warrant the publication of this 



' The amphibian nucleolus is said by Carney 

 and Lebrun to contain a small amount of nucleo- 

 albumin. 



'Jour, of Physiol., Vols. 17 and 18. 



'Cf. Moroff, Arch. f. Zellforsohung, Vol. 2. 



* Arch. f. Protistenkunde, Vol. 5. 



' Walker and Tozier, Quart. Jour, of Exper. 

 Physiol, Vol. 2. 



preliminary note pending the completion of 

 the work. 



The pistils of the lilies are in general alike. 

 However, certain differences exist among them 

 (1) in regard to the formation of the parti- 

 tion walls of the ovary and (2) in regard to 

 the development of the ovules. It is the pre- 

 vailing opinion among botanists that the mar- 

 gins of the carpels in the Liliaeese infold to 

 form the partition walls of the ovary and also 

 to produce the ovules. This is true of some 

 lilies hut it is not true of all lilies. It has 

 been found that certain lilies develop the par- 

 tition walls of their ovaries, also their ovules, 

 from the middle portion of their carpels. In 

 this type of ovule-production the midribs of 

 the carpels become thicker, push in to the 

 central axis of the ovary, unite and produce 

 the ovules. 



The following plants have been found to 

 develop their ovules from the midribs of their 

 carpels: Lilium longiflorum Thunb., Lilium 

 longiflorum eximium Nichol., Lilium candi- 

 duni Linn., Eryihronium albidum Nutt., Con- 

 vallaria majalis Linn., Tradescaniia hracteata 

 Small, Zebrina pendulata Schnitzl., Tulipa sp. 

 Charles E. Temple 



The University of Nebraska 



SOCIETIES AND ACADEMIES 



THE IOWA ACADEMY OF SCIENOE 



The twenty-third annual meeting of the Iowa 

 Academy of Science was held at the State Uni- 

 versity, Iowa City, on April 31 and May 1. A 

 public meeting was held on the evening of April 

 30 for the presentation of the address of the presi- 

 dent, Professor Samuel Calvin, on " The Work 

 of the Iowa Geological Survey," and a lecture by 

 Professor William A. Locy, of Northwestern Uni- 

 versity, on " The Service of Zoology to Intellectual 

 Progress." Before the beginning of the evening 

 program Professor C. E. Seashore gave demonstra- 

 tions of the tonoseope in his laboratory. 



In the progress of the two sessions of the acad- 

 emy the following papers were presented : 

 Comet C, 190S { Morehouse) : D. W. Mobehotjse. 



An account of the comet discovered in Sep- 

 tember, 1908, while photographing at the Yerkes 

 Observatory. 

 The PolyporacecB of Fayette, Iowa: Guy West 



Wilson. 



