354 Jacob Parsons Schaeffer. 
mens. Out of SO specimens examined 35 showed accessory ostia, 
or a percentage of 43; while three cases had two accessory ostia, or a 
percentage of 3.75. From this it seems that the former figures 
were much too low. Whether this series had a special run for 
accessory ostia or whether too few specimens were used in the 
former reports is of course not known. It may, however, be 
said that the opening occurs very frequently and that the ear- 
lier reports, apparently, placed the percentage of occurrence far 
too low. 
Just what the ostium maxillare accessorium means in all cases 
is indeed difficult to say. It seems almost incredible that so 
large a percentage of specimens should have pathological open- 
ings. Giraldés bases his claim of a pathological origin on the 
facts that the accessory ostium is absent in the young individ- 
ual, and that the mucous membrane becomes thinned out in this 
locality—even though the opening fails to establish itself. Zuck- 
erkandl corroborates the thinning of the mucous membrane in 
this locality at times, but claims that we have no evidence that it is 
always a pathological process causing this condition. He says 
that occasionally the accessory opening is caused by neighboring 
structures. 
Seltenenfalls entsteht ein Ostium maxillare accessorium durch Druck 
von Seite nachbarlicher Organe; ich habe gesehen, das ein abnorm breiter 
zugespitzer Hakenfortsatz der Nasenscheidewand an der hinteren 
Nasenfontanelle eine Durchlocherung veranlasst hatte. 
I have not found the accessory ostium present in the fetus and 
infant. Unfortunately I have been unable to secure a sufficient 
number of specimens between the ages of 6 and 15 years to draw 
any conclusions of value on the occurrence of the ostium maxillare 
accessorium during this period of time. I found the accessory 
opening occasionally present in the young adult—17 to 20 years. 
The specimens (adult) studied, ranged in age from 17 to 80 
years, with the majority from subjects over 50 years old. That 
some cases of accessory ostia are of pathological origin is doubt- 
less true, but many cases certainly do not give any evidence 
of a pathological process. The thinning of the-mucous membrane. 
