In the present study, I immobilized the liver homogenate from a pig on the alginate gel beads. A large quantity of the homogenate-immobilized beads were prepared easily with alginate and calcium chloride solutions.

The beads were milky white and the suspension was clear and not colored by the blood pigments for at least 4 days. So, the beads and their suspension were suitable for detection of color developed by enzyme reaction. When the beads were kept in dark at 5°C for 3 days, the catalase activity on the beads suspended in 0.15 mol/l sodium chloride solution retained 84% of the original activity, and that in 0.1 mol/l Tris buffer solution (pH7.4) retained 75%. Thus, the beads were no problem for experiments when they were used within 1-2 days after preparation.

I measured successfully the activity of catalase, alcohol dehydrogenase and alginase using the beads; the catalase activity was measured in various temperatures by trapping 02 evolved into a special test tube which was newly devised in the present study. Alcohol dehydrogenase activity was detected by the coluring of beads developed with INT reagent. Urea formed by alginase was decomposed into ammonia by added urease, then the latter was detected with Nessler’s reagent on filter paper.

It was found that the enzyme-immobilized beads were more suitable than homogenate or small piece of liver for some experiments in biology in high school.

The outdoor swimming pools of elementary and junior high schools in Tsu City, Mie Prefecture, were surveyed to clarify the community structure of odonate larvae. During 3 years, in 34 pools, we found a total of 13 species of odonate larvae, 2 of them were Zygoptera and 11 were Anisoptera. Crocothemis servilia mariannae, Orthetrum albistylum speciosum and Sympetrum infuscatum were common species in the pools examined in late May. The odonate community at the pools located in the hills showed a higher diversity index than that at the pools located in the plains. The larval density was approximately constant irrespecitive of the environment of the pools, 1 individual larva per meter of the bottom of pool along its longer side (25m). In early June when the water was drained for pool-cleaning, the odonate and the other aquatic insect communities were catastrophically destroyed. Larvae of Pantala flavescens were dominant at all pools in autumn. Very few larvae were collecled in the winter. In this study we discussed the odonate larvae as a teaching material for biology and the environment.