CONTENTS 
No. 1. JANUARY 
Rospert H. Bowen. On certain features of spermatogenesis in amphibia and insects. 
IAN WiO) TOVEHIGSH GIO NEN CIS bea 1kea DI) eae GMP Dina eeu Game no acleocu sete dormers ce cilioerc oer 1 
E. V. Cowpry. The reticular material as an indicator of physiologic reversal in secretory 
polarity in the thyroid cells of the guinea-pig. Two plates (fourteen figures).... 25 
WarRREN H. Lewis. Endothelium in tissue cultures. Five plates (twenty-four figures). 39 
Otto F. KaMpMEIER. The development of the anterior lymphatics and lymph hearts in 
anuran embryos. Thirty-five figures including eight colored plates................ 61 
Hautsty J. Baga. Disturbances in mammalian development produced by radium 
emanation. Ten text figures and three plates (figures eleven to fifteen)............ 133 
No. 2. MARCH 
Epwarp A. Boypen. The development of the cloaca in birds, with special reference 
to the origin of the bursa of Fabricius, the formation of a urodaeal sinus, and the 
regular occurrence of a cloacal fenestra. Forty-one figures.....................-..- 163 
Ivan E. Watirn. On the nature of mitochondria. I. Observations on mitochondria 
staining methods applied to bacteria. II. Reactions of bacteria to chemical treat- 
Pole Ta he CMEC PUBIC (RUIN G) AEUIT CS). cs 51%. sido ovesc 5. 5,30 51.0e A ae OPS Pao roe oes crete a arabes 203 
BEATRICE WHITESIDE. The development of the saccus pedal mphaticus i in Rana tem- 
Pekar a oiiies Nineteen) HP WEES .f.x.5\iuto.s <x» alaie's ate eaaees oP wh trerasn ht eso wes 231 
Ne-'3.. - NDA. 
Hersert G. Witutson. The terminals of the human bronchiole. Nine figures.......... 267 
Epagar ALLEN. The oestrous cycle in the mouse. Twenty-four figures................ 297 
BraDLey M. Patten. The formation of the cardiac loopin the chick. Two text figures 
PRR RER CELL CEI oh enee asf erry oil aya ca: a.al's-<) «01 ara SNe epee eta e «= oben evniae RMR eyes 373 
No; 4.. JULY 
R. S. CunnineHam. The reaction of the cells lining the peritoneal cavity, including the 
germinal epithelium of the ovary, to vital dyes. One plate (eight figures).......... 399 
Raymonp M. Setue. Changes in the vaginal epithelium of the guinea-pig during the 
Genmous cycle.  Dhree: plates (eleven figures)... 6.6. 008s oes ce eee sk weew ac cpin soe 429 
ui 
