EXPERIMENT STATION REPORTS. 175 



number of cases studied, however, is not sutiicient to justify any con- 

 clusions at this time, lender this head Ave are attempting to trace the 

 avenue of invasion of ail)ortion infection in experimentally inoculated 

 heifers. This [ihase of the problem requires a j^reat amount of routine 

 examination but it is of considerable scientific interest and practical im- 

 portance. 



The greatest amount of time has been spent upon the third subdivision 

 of this project. Our observations are very interesting but we are not 

 sure yet that we are able to inter])ret them. Considerable time has 

 been spent uj»on a method of staining botli dram negative and (iram 

 positive organisms in sections from the reproductive organs of pregnant 

 cattle, with considerable success. 



The method is a cond)ination of (loodi)asturi/> and the AVeigert Fiibrin 

 stain. By this metliod we are able to demonstrate lai-ge numbers of cell 

 inclusions in both the chorionic and nmternal epithelium of the placental 

 and interplacental areas. These inclusions are present in large numbers 

 and resemble abortion hacilli. We tind them in large numbers in posi- 

 tively reacting animals and also in negatively reacting animals, also 

 in animals from which abortion bacilli are obtained by cultural or in- 

 oculation methods and in animals from which no micro-organisms are 

 obtained by such methods. All cases studied so far liave been from abor- 

 tion infected herds. — ». 



In spite of their close resendilance to abortion bacilli we are not yet 

 in a positoin to say that they are micro-organisms. Their presence is 

 associated witli well-marked granular degeneration and necrobiosis of 

 the epithelium. Other than this, in those cases in which other forms, 

 such as streptococci, stei»hylococci and larger rods cannot be found, 

 there is but little evidence of tissue reaction. That is, there is no well 

 marked leucocytosis, intlamniatory exudate (other than numerous 

 placental hemmorrhages i nor tissue proliferation. In some cases where 

 other forms of micro-organisms are observed in sections evidence of 

 proliferation of the connective tissue leading to thickening of the walls 

 of the crypts is observed. If this is a frequent condition, it would ex- 

 plain retention of the placental membrane. The Oranular degeneration 

 of the placental epithelium is so marked in some cases that one might 

 suspect that it would influence the interchange of nutritive and meta- 

 bolic products between dam and fetus. We have made some observations 

 that lead us to suspect that this is the case although we are not ready 

 to draw any conclusions. 



In a few cases in which extensive granular degeneration of the placen- 

 tal epithelium is seen we have observed what we suspect as an attempt 

 to bring about attachment of the chorion and maternal mucosa in the 

 interplacental areas. Nonnally the general opinion is that there is no 

 connection in the bovine, between the chorion and uterine mucosa in 

 the inter carnnculiP areas and that the maternal epithelium in these 

 areas retains the adult type during pregnancy. We have observed 

 changes in these areas that appear to us identical Avith those changes 

 observed in the plancental areas. That is, in these areas, the maternal 

 epithelium appears to have acquired the vegetative type, primary villi 

 are seen to have grown out from the chorion and there is a correspond- 

 ing outgrowth of the uterine mucosa, apparently the result or stimuli 

 prising in the chorion. This condition has been o^bserved before by other 



