1) The body weight of the chick embryo is increased, though slightly, by the treatment with procaine penicillin-G, while bornylamine penicillin-G acts inhibitorily on the development. The action of bornylamine itself is also inhibitory to the development.
2) The amount of allantoic fluid is not particularly influenced by either procaine penicillin-G, bornylamine penicillin-G or by bornylamine hydrochloride.
3) In the cases treated with bornylamine penicillin-G or with bornylamine hydrochloride, malformations in the chick embryo are noted, while no such malformations are observable in the cases treated with procaine penicillin-G. In either of the above cases, perfect hatchings were successfully accomplished.
4) Even in the cases treated with 12 mg of procaine penicillin-G, the amount of penicillin excreted in the allantoic fluid is only minute. Similarly to the above, the amount of penicillin excreted in the allantoic fluid is also minute even in the cases treated with 12 mg of bornylamine penicillin-G.
5) The damage on the liver cells inflicted by procaine penicillin-G is relatively mild, while the damage inflicted by bornylamine penicillin-G is fairly severe. The damage on the liver cells inflicted by bornylamine hydrochloride is even more severe compared with those by bornylamine penicillin-G.
In short, among procaine penicillin-G, bornylamine penicillin-G and bornylamine hydrochloride, only procaine penicillin-G acts slightly promotingly on the development of chick embryo, while bornylamine penicillin-G and bornylamine hydrochloride act inhibitorily. The damage on the liver cells inflicted by procaine penicillin-G is also milder compared with those inflicted by the remaining two substances. Further experiments revealed that the damage inflicted on the liver cells and the development inhibitory action are originated from the bornylamine which is the constituent of bornylamine penicillin-G. Furthermore, the major part of the procaine penicillin-G or the bornylamine penicillin-G given to the chick embryo is considered to be splitted within the body of the chick embryo since the amounts of procaine penicillin-G and bornylamine penicillin-G excreted in the allantoic fluid are minute.