Journal of Applied Microscopy. 



217 



striking feature in the new species, as in 

 P. californica, is the presence of two dis- 

 tinct types of cells in the colony. Four 

 vegetative cells constitute the anterior 

 polar circle and are directed forward in 

 locomotion. The rest of the cells are 

 gonidial. The paper is illustrated by a 

 plate showing the mature form and sev- 

 eral stages in development. The follow- 

 ing description will enable any one to 

 recognize the species. 



Pleodorina illinoisensis. ni sp. — Number 

 of cells in a colony usually thirty-two, 

 rarely sixteen or sixty-four. Dimensions 

 of colony range from 46x38 yt/ to 200x175//. 

 Vegetative cells always four in number. 

 Gonidial cells approximately one and 

 one-half times the diameter of the vege- 

 tative cells. Known habitat, submerged 

 lands along the Illinois river. Types 

 deposited in the collections of the Illinois 

 State Laboratory of Natural History and 

 in the United States National Museum. 



C. J. C. 



Klebs, Georg. Zur Physiologie der Fortpflan- 

 zung einiger Pilze. 8. Sporodinia grandis, 

 noting particularly what conditions induce 

 growth o"f the sextual or asexual organs. 



Transpiration, induced by whatsoever 

 cause, is the most common factor causing 

 sex organs. The food, however, must be 

 appropriate, i. e., must contain proper 

 carbohydrates. Parthenogenesis always 

 resulted on reducing the air pressure to 

 about 50 mm. of mercury, while below 15 

 mm. the plant was sterile. A trace of 

 acid salt favors zygote formation, while 

 acids or normal salts restrict it. Spor- 

 angia, in general, appear under condi- 

 tions which prohibit zygote formation. 

 This explodes the prevalent idea. Owing 

 to the accelerating influence of light on 

 sporangium formation, pure cultures of 

 sporangia could be obtained by placing 

 covered beakers, containing cultures, in 

 the sunlight. The effect or humidity was 

 counteracted by the light and sporangia 

 resulted, while purity was promoted by 

 the cover. 



F. L. Stevens. 



Chicago. 



Bela,jeff, Wl. Die verwandschaftlichen Bezie- 

 hungen zwischen den Phanerogamen und den 

 Cryptogamen in Lichte der neuesteu Forschun- 

 gen. Biol. Centralbl. 18 : 209-218, 1898. 



This paper presents a critical review of 

 previous work upon the gametophyte 

 structures of Bryophytes, Pteridophytes, 

 Gymnosperms, and Angiosperms. Homo- 

 logies are traced in a masterly manner. 

 The female prothallium shows a gradual 

 transition from Cryptogams to Phanero- 

 gams, but the author does not attempt to 

 interpret the puzzling structures of the 

 Angiosperm embryo-sac. The male 

 prothallium furnishes a still more 

 gradual transition from Cryptogams to 

 Phanerogams. The discovery of sperma- 

 tozoids in Gymnosprems is another proof 



of the relationship between the vascular 

 Cryptogams and Cycads. C. J. C. 



RECENT LITERATURE. 



Cavara, F. Intorno ad alcune strutture nucleari 



Atti dell Instituto botanico della. R. Univer- 



sita di Pavia. II, 5 : 1-49, 1898. 

 Ikeno, S. Untersuchungen ueber die Entwicke- 



luiig der Geschlechtsorgane und den Vorgang 



der Befruchtung bei Cvcas revoluta. Jahrb. f. 



wiss. Bot. 33 : 557-603, 1898. 

 Klebahn, H. Ueber den gegenwaertigen Stande 



der Biologie der Rostpitze. Bot. Zeit. 56 : 145- 



158, 1898. 

 Liuestner, G. Beitraege zur Biologie der Sporen. 



Bot. Zeit. 56 : 198, 1898. 

 Mitrophanow, P. Beobachtungen ueber die Dia- 



tomen. Flora, 85 : 293-314, 1898. 

 Nathansohn, A. Beitraege zur Kentniss des 



Wachsthums der trachealen Elemente. Jahrb. 



f. wiss. Bot. 33 : 671-686, 1898. 

 Osterwalder, Adolf. Beitraege zur Embryologie 



von Aconitum napellus. Flora, 85 : 254-292, 



1898. 

 Pammcl, L. H. Comparative anatomy of the 



corn caryopsis. Rep. of Iowa Acad. Sci. 5 : 



(No. 10, pp. 1-5), 1898. 

 Wille, Dr. N. Beitraege zur physiologischen Ana- 

 tomic der Laminariaceen. 



Animal Biology — Current Litera- 

 ture. 



Separates of papers and books on animal biology 

 should be sent for review to Agnes M. Claypole, 

 Sage College, Ithaca, N. Y. 



Jander, K. Chromsalpetersaeure als Piegment 

 Zerstoerendes Mittel. Zeitschrift f. Wiss. Micro- 

 scop., 15: 1898. 



The author has been using the means 

 he describes for removing pigment from 

 animal tissues since 1891, and always with 

 certainly good results. It is a process 

 already known as a means for hardening 

 and was first proposed by Fol: 



Chromic acid 1 per cent, sol 70 parts 



Saltpeter 3 parts 



Water 200 parts 



It has long been known that black cr 

 brown pigment could be destroyed by 

 chromic acid and potassium bichromate, 

 but since the process required several 

 weeks for completion it was not gener- 

 ally applicable. The chromo nitric acid, 

 on the contrary, destroys pigment very 

 quickly, so that the tissue is neither made 

 brittle or otherwise changes. Tissues 

 were first fixed in the best way to pre- 

 serve their structure, and then washed; 

 when the pieces of tissue were easily per- 

 meable they were carried from strong 

 alcohol back to water, and then put in 

 the decolorizing mixture for twelve to 

 twenty-four to forty-eight hours, and the 

 pigment was completely removed. 



Large pieces of tissue, more diflflcult 

 of penetration, which can be sectioned, 

 were cut first and then decolorized. The 

 only difficulty in this process is that sec- 

 tions fixed to the slide with water are 

 apt to be loosened, and thin albumen 

 fixative Is hence necessary; with tliat 



