August 15, 1913] 



SCIENCE 



233 



by Dr. Th. v. Karman, who, although a very 

 young man, has no need to apologize for his 

 article, which, although containing fewer for- 

 mulae, is written with great clearness and has 

 even better cuts than the English article. To 

 be sure Dr. Karman had the advantage of 

 reading Professor Love's article as well as his 

 great treatise, but the article is decidedly inde- 

 pendent, and concludes with an excellent treat- 

 ment of elastic hysteresis or Nachwirkung, 

 which is becoming more and more important, 

 and which we do not find mentioned in Pro- 

 fessor Love's article. Very likely this is also 

 due to the more recent appearance of the Ger- 

 man work. For the biologist we will mention 

 the fifty-three-page article on Descendenzthe- 

 orie, profusely illustrated, as compared with 

 the " Britannica " article on Evolution, of 

 fifteen pages, without illustrations. 



A feature of the present work that is of 

 great importance is found in the biographical 

 sketches, which, although very short, are de- 

 cidedly helpful. We have looked in vain for 

 the name of Mendel, but find three genera- 

 tions of Becquerels. It is a pleasure to note 

 throughout the work frequent references to the 

 work of Americans, living and dead, of whom 

 we may mention Rowland, Newcomb, Michel- 

 son, E. W. Wood, Campbell, E. B. Wilson and 

 W. M. Davis, whose familiar hand is recognized 

 in the admirable drawing of meanderings in 

 the article Fluss. This fact, which is now be- 

 coming more and more general, may partially 

 reconcile us to the state of affairs upon which 

 we have commented at the beginning. It may 

 seem premature to review a work that is not 

 yet finished, but it seems of importance to call 

 the attention of the public to this very impor- 

 tant and desirable work. 



Arthde Gordon Webster 



July 26, 1913 



Siudien an intracellularen Symhionten. I. 

 Die intracellularen Symhionten der Hemip- 

 teren. By Dr. Phil. Paul Buchner, Pri- 

 vatdocent in the University of Munich. 

 Eeprinted from "Archiv fiir Protisten- 

 kunde," Vol 26. Jena, 1912. Pp. 116, 12 

 plates and 29 text figures. 



For many years students of insect morphol- 

 ogy and embryology have noted in the fat 

 body of larval and adult insects and in certain 

 eggs and embryos, peculiar corpuscle- or rod- 

 like bodies, seemingly extraneous in origin 

 and whose nature and function could not be 

 satisfactorily explained. 



Thus, as far back as 1850, Leydig observed 

 the appearance, in embryos of viviparous 

 aphids, of " a green or yellow granular mass 

 which at first apparently lay free between the 

 cells, but later massed in spherical form, be- 

 came enclosed by a membrane, and took part 

 in the formation of the vegetative organs of 

 the insect." This constituted the mass later 

 designated by Huxley and by Lubbock as the 

 " pseudovitellus," a name very generally ac- 

 cepted by embryologists, though some have 

 regarded the mass as having a very specific 

 function. According to Babiani, who demon- 

 strated its origin within an enlarged cell of 

 the follicular epithelium, it represents the 

 vestigial male sex gland of the agamic indi- 

 vidual. On the other hand, Witlaczil re- 

 garded it in the form of the " green body " of 

 the adult aphid, as an excretory organ, re- 

 placing the Malpighian tubes which are lack- 

 ing in some species. 



Of less striking appearance are the bac- 

 teroidal bodies found by Blochmann, '84, in 

 the eggs of certain ants and, later, studied 

 more fully by him in the eggs and adult fat 

 body of Blatta and Periplaneta. These little 

 bodies, which Wheeler, '89, called Blochmann's 

 corpuscles, have also been found in the larval 

 fat cells of Pieris and in various orthoptera. 

 They are in the form of minute, straight or 

 slightly bent rods, 6-8 ju long and, as Bloch- 

 mann was able to determine, multiply by cross 

 division. He was unable to cultivate them, 

 but regarded them as symbiotic bacteria. 



In recent years there has accumulated evi- 

 dence to show that these scattered structures 

 are related and that Blochmann was right in 

 interpreting them as symbiotic forms. Many 

 such suggestions appear in the literature of 

 the past fifteen or twenty years, but it is espe- 

 cially the work of Mercier (1906), Sulc (1906 



