310 



SCIENCE 



[N. S. Vol. LIV. No. 1395 



The distribution of the European elm scale: 

 Albert Hartzell. 



Further studies of the relative position of the 

 maxima contractions of the amphiliian muscle when 

 subjected to the various ranges in temperature: 

 K. L. Pakker. 



Cytology of the large nerve cells of the crayfish 

 (Cambarus) : L. S. Boss. 



Tlie readjustment of the peripheral lung motor 

 mechanism after bilateral vagotomy: T. L. Pat- 

 terson. 



A new Trematode parasite of the TJnionidw: 

 Harry M. Kelly. 



Two insect pests on clover: H. E. Jaques. 



Methods of teaching parasitology : Herbert E. 

 Werner. (Posthumous.) 



Insect parasitism with special reference to para- 

 sitic Diptera: Ivan L. Eessleb. This paper is a 

 review of the important publications which have 

 appeared since 1602, on insect parasitism, when the 

 exit of the Hymenopterous parasite, Apanteles 

 glomeraitus L., from the commoii cabbage butterfly 

 was observed. Parasitism as a factor in insect 

 control is discussed as well as other natural agen- 

 cies of control. The various families of the Dip- 

 tera are classified with reference to their preda- 

 tory or parasitic characteristics. The biology of 

 the Tachinidse which is probably one of the best 

 known of the parasitic Diptera, is discussed at 

 length. 



BOTANY 



Notes on the genus Catherinea in Iowa. — I : Lucy 

 M. Cavanatjgh. a discussion of variation in leaf- 

 characters in this genus as represented in Iowa. 



The use of common names for plants: B. 

 Shimek. a presentation of some objections to 

 the use of "common names" for plants. 



A prairie grove in eastern Illinois: B. Shimek. 

 a discussion of an isolated grove on the prairies 

 at Eoyal, Illinois, and the evidence which it offers 

 towards the solution of the problem of the tree- 

 lessness of the prairies. 



Some noteworthy fungi from South Carolina: 

 Guy "West Wilson. 



Dr. Sudolph Gmelin and his collection of Min- 

 nesota, Wisconsin and Iowa plants: E. I. Cratty. 

 Dr. Gmelin lived for many years practicing his pro- 

 fession as a physician and surgeon at Elkader, 

 Iowa, and other points, and a brief biographical 

 sketch and a list of plants collected by him is pre- 

 sented. 



Two additions to our list of Cruciferae: E. I, 

 Cratty. A brief paper on Brassica juncea (L.) 

 Cosson, the Indian mustard, and Lepidium perfo- 

 liatum L., a recent emigrant from the old world. 



A brief survey of economic botany: L. H. Pam- 



MEL. 



Studies in the germin-ation of some woody 

 plants: L. H. Pammel and Charlotte M. King. 



Some wound responses of foliage leaves : Egbert 

 B. Wylie. 



Notes on phycomycetes : I. E. Melhus. 



A list of some of the phycomycetes in Iowa: J. 

 M. Eaeder. 



A key to the plant families of central Iowa: 

 Winifred Ellsworth and Henby S. Conard. 



Fossil plants and classification: Henry S. Con- 

 ard. 



A study of tJie vegetation of Austin Bluffs, near 

 Colorado Springs, Colorado: T. J. Fitzpatrick. 

 An intensive study was made of this area during 

 the summer of 1920. As the location occupies an 

 intermediate position between that of the plains on 

 the one side and the mountains on the other its 

 flora is an interesting one. 



CHILD WELFARE 



Besearch in the field of mental and physical de- 

 velopment of children: B. T. Baldwin and Lorle 

 I. Stecher. 



IOWA section, mathematical association op 



AMERICA 



Correlation between mental tests and grades in 

 mathematics of freshman engineering students: 

 Marla M. Egberts. 



Playing with the sine and projection formulas: 

 W. J. EusK. 



Certain summation formulas: John F. Eeilly. 



Some properties of the function w^tanh z: F. 

 M. Weida. 



Derived solutions of differential equations: M. 

 E. Graber. 



The surface z^logy^: C. W. Emmons. 



Circles mutually tangent and tangent to concen- 

 tric circles at specific points: C, W. Wester. 



A study of certain reports of the "National 

 Committee on Mathematical Requirements" : Com- 

 mittee Eeport. J. V. McKelvey, Chairman. 

 James H. Lees, 



Secretary 



