360 



SCIENCE 



[N. S. Vol. XLIX. No. 1267 



known investigations. Van der Stricht haa 

 written on tlie genesis and structure of the 

 membrana tectoria and crista spiralis of the 

 cochlea, and Duesberg on " la fecondation des 

 ascidiens " — a study of chondriosomes. Cow- 

 dry likewise has dealt with the mitochondrial 

 constituents of protoplasm and has supplied 

 a shorter paper on the chromophile cells of 

 the nervous system. Mitochondria in nerve 

 cells are quantitatively considered by Madge 

 D. Thurlow. The transitory cavities in the 

 corpus striatum are described by Essiok. Two 

 papers deal with tissue cultures, the occur- 

 rence of binucleate cells being described by 

 Macklin, and the development of connective 

 tissue fibers by Margaret E. Lewis. Miss 

 Sabin, through series of fine injections, stri- 

 kingly reproduced, has traced the transforma- 

 tion of the posterior cardinal veins of pig em- 

 bryos, and, in a second paper, the origin of 

 the primitive vessels in the chick. Streeter 

 has advanced the study of the cerebral sinuses, 

 which have been beautifully drawn, and has 

 described also the formation and spread of the 

 periotic tissue spaces. Weed's important work 

 on the development of the cerebrospinal spaces 

 forms the whole of Volume 5. Clark inter- 

 prets an extraordinary anomaly of the thoracic 

 duct, and Cunningham describes the pul- 

 monary lymphatic vessels of pig embryos. 

 There are three monographic studies of normal 

 human embryos, by Ingalls, Johnson and 

 Watt; and a specimen with spina bifida is 

 described by Miss Wheeler. Corner reports on 

 the corpus luteum in the pig. Meyer has a 

 statistical study of prenatal growth, based on 

 obstetrical records, and Shipley and Wislocki 

 jointly, interested in the chemical products of 

 the poison glands of Bufo agua, a tropical 

 toad, describe the histology of these epine- 

 phrin-producing glands. In the twenty-sixth 

 and last contribution, Kunitomo deals with 

 the retrogression of the caudal end of the 

 spinal cord and the decline of the tail in 

 human embryos. 



The contributions are irregularly grouped 

 in small volumes which are sold separately. 

 Doubtless it would be appreciated if a limited 

 number of the separate articles were offered 



to embryologists, though every institution 

 needs the complete file. Altogether it is a 

 journal to be studied by those responsible for 

 our anatomical publications. When the Amer- 

 ican Journal of Anatomy was founded and 

 was being published in Baltimore largely under 

 Mall's direction, it seemed that nothing better 

 was likely to appear in this country. But as 

 the Journal became securely established, losing 

 — perhaps we imagine it — the enthusiasm of 

 tlie earlier volumes, Mall's genius for publica- 

 tions sought new fields. His Contributions 

 have caught in beautiful form and permanent 

 record the spirit and purposes of current 

 American investigations in embryology, and 

 their future is full of promise. 



Frederic T. Lewis 

 Harvard Medical School 



SPECIAL ARTICLES 



NOTE ON THE TECHNIQUE OF SOLUTION 

 CULTURE EXPERIMENTS WITH PLANTS 



In recent years a large number of sand and 

 solution culture experiments have been carried 

 out by various laboratories. It is becoming 

 recognized that any complete understanding 

 of soil fertility requires an insight into the 

 absorption and metabolism of the plant as 

 well as the nature of the soil solution. In 

 connection with some investigations relating 

 to the latter question, this laboratory has 

 undertaken a series of studies on the effect of 

 concentration and reaction of the nutrient 

 solution on the growth and absorption of the 

 barley plant. Incidental to this work it has 

 been necessary to examine somewhat critically 

 several phases of the technique employed in 

 sand and solution cultures, and it is desired to 

 present here a number of considerations bear- 

 ing on the interpretation of these experiments. 



Ordinarily the conclusions from such in- 

 vestigations have been based on the concentra- 

 tions and composition of the solutions as 

 originally prepared. In very few cases have 

 analyses been made of the solutions after con- 

 tact with the plant, nor of the plants them- 

 selves. It is not known therefore exactly 

 what was the condition of the solution during 

 the periods between changes. The percentage 



