Although several important studies are noticed in the indirect method for measuring the blood pressure in mice, each of them involves some ambiguities in the values obtained because mice are too small to handle.
In mice or small laboratory animals, the direct method, which is performed by cannulation into the carotid artery, is so far admitted as the most reliable device.
In the present experiment, establishment of a systematized procedure, which is rather easy and widely applicable for physiological observations using small animals was intended. Since the cannulation in small experimental animal must be done without hemorrhage, the experiment was started from the modification of the method recently published by SUZUTA and OKUGI. Influences of electroshock as pretreatment in the authors' method reported in the previous paper were discussed at the same time, especially noticing the blood pressure.
The results summarized are as follws :
1) The cannulation into the carotid artery was achieved under drowsy state following the electroshock (30volt-3sec.) .
2) The head cervical region of mice were suitably fixed with clay on a board.
3) Weight of the cannula was possibly lightened and the point of the needle was blunted in order to avoid an unexpected damage of the artery.
4) The arterial blood pressure obtained in normal state was 79-132 mm Hg.
By using the modified method, observation or measurement of the carotid blood pressure in mice can be persued much more easily in any case: for example, even in the convulsion.

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The effects of Neguvon ‘Bayer’ were examined on some endo- and ectoparasites of mice by 2 weeks' oral administration with drinking water.
In a concentration of 0.1 per cent, showing no influence to the development of body weight of animals, significant decrease of Syphacia obvelata was observed. The Hymenolepis nana was affected slightly, and Liponyssus bacoti was found to resist against it. L. bacoti could be easily eliminated by soaking the animals once in 0.04 per cent solution of the drug without an apparent toxicity.
Histologically were seen slight but apparent degenerations in the liver cells, which persisted at least for 2 weeks after the administration.

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Twenty-one-day-old male rats of the Donryu-strain supplied by the Central Laboratories for Experimental Animals were fed CLEA chow CE-2 in our airconditioned animal house.
Animals were observed clinlcally and autopsied at the age of 21-180 days.
1. At autopsy, the body weight, body and tail length were measured. In the growth curve of the body weight, a plateau was seen after 80 days and in the case of body and tail length it was seen after 50 days. Curves showing increase of organ weights are presented in Fig. 5-A-5-F. The weight curves are plateaued respectivey after 50 days in thyroid, submaxillarry glands, stomach, liver, heart, and brain, after 70 days in testis, ventral prostates, adrenals and hypophysis, after 80 days in epididymides, pancreas and M. levator ani, after 90 days in fat bodies. The weight of thymus showed a peak at 50 days of age and decreased there after.
2. The period of sexual maturity was estimated to be 50 days of age, because the matured sperms were observed in epidymal tail.
3. During 22nd-87th day, there was no significant difference in the ratio of the fecal weight and the food intake.
4. Zonary thing of back hair along the spinal column was observed frequently in animals of 35-47 days of age.
5. Accessory adrenals were detected in 62.8% of rats. Deformity of kidney were observed in 2 out of 498 cases. Testicular atrophy was observed in 40 out of 60 cases after 140 days of age.
6. During 50-90 days of age, chronic nasal infection was observed in an appreciable number of rats which resulted the death of some animals due to acute pneumonia.

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