Put a bug in the water drop on the glass slide and slowly put a little magnesium sulfate crystal in the water drop on the glass slide. It can be seen that the insects are gradually anesthetized. Under the stereomicroscope, we can see a tubular structure protruding from the mouth, which is pharynx. Half-covered, put the Petri dish under light for a moment, and observe the phototaxis reaction of the planarian.

Put the worm that has been hungry for several days in a small beaker, mix the cooked egg yolk with magenta powder and feed it to the worm. 1-2 hours later, the inside of the worm was red with naked eyes. Remove the worms from the slide and observe the red intestinal branches under low magnification.

excretory system

Take the worms that have been hungry for a few days, put them in the water drops on the glass slide, cover them with a cover glass when the worms stretch, and then gently press the worms with the rubber head of a pencil to make them disperse evenly. At this time, the broken tissue overflowed. Under the low-power microscope, we can see a series of irregular flashes on both sides of the worm. Choose an empty place and turn to a high-powered lens for observation. It can be seen that there are tiny pipeline branches in the flash evaporation, in which the liquid continuously flows directionally. The boundary of the flowing liquid is the wall of the protorenal duct, and the flash is caused by the cilia swinging in the flame cells at the end of the branch of the protorenal duct.

nervous system

Nerve and sensation: trapezoidal nervous system, with a pair of cranial nerve ganglia in the head, a pair of ventral nerve cords leading from the cranial nerve ganglia to the body, and transverse nerves connecting the ventral nerve cords to form a trapezoid.

At low magnification, the whole turbot showing the nervous system shows a pair of ganglia in front of the body. Therefore, there are two longitudinal nerve cords along both sides of the body, and there are many transverse nerve connections between the cords, which are trapezoidal. The brain sends nerves to all parts of the eyes and ear processes.

genital system

Androgyny, take a whole slide specimen of planarian showing reproductive system and observe it under the microscope.

Female reproductive system: There are/kloc-0 pairs of ovaries in the front and back of the eyes, which are dark and round. There are/kloc-0 fallopian tubes in both ovaries, which go backwards along both sides of the body, meet at the back of pharynx and enter the reproductive cavity. There is an oval seminal vesicle in front of the reproductive cavity, which also leads to the reproductive cavity. There are many granular yolk glands outside the fallopian tubes on both sides.

Male reproductive organs: There are many spherical testes parallel to fallopian tubes on both sides of the worm, and each testicle is connected with 1 pair of vas deferens through a vas deferens (which is difficult to dredge), and the vas deferens expand on both sides of the pharynx to form seminal vesicles; The seminal vesicle merges into a penis in front of the reproductive cavity, and the penis enters the reproductive cavity. There is a reproductive hole in the reproductive cavity.