. Elementary botany . tered over this portion of the prothallium. These are the an- theridia. Ifthepro- thallia have not been watered for a day or so, we may have an opportunity of see- ing the spermato- zoids coming out of the antheridium, for when the prothallia c .. , +1 ... ' 1 Section of anthendia showing sperm cells, and spermato- are freshly placed in «>ids in the one at the right. water the cells of the antheridium ab- sorb water. This presses on the con- tents of the antheridium and bursts the cap cell if the antheridium is ripe, and all the spermatozoids are shot out. We ca
. Elementary botany . tered over this portion of the prothallium. These are the an- theridia. Ifthepro- thallia have not been watered for a day or so, we may have an opportunity of see- ing the spermato- zoids coming out of the antheridium, for when the prothallia c .. , +1 ... ' 1 Section of anthendia showing sperm cells, and spermato- are freshly placed in «>ids in the one at the right. water the cells of the antheridium ab- sorb water. This presses on the con- tents of the antheridium and bursts the cap cell if the antheridium is ripe, and all the spermatozoids are shot out. We can see here that each one is shaped like a screw, with the coils at Fig. 224. r ' Different views of spermatozoids; first close. But as the SpermatOZOid 42, 43, in a quiet condition; 44, in , , . r motion (Adiantum concinnum). begins tO move this COlI Opens SOme- what and by the vibration of the long cilia which are on the smaller end it whirls away. In such preparations one may often see them spinning around for a long while, and it is only when they gradually come to rest that one can make out their form. 373. Archegonia.—If we now examine closely on the thicker part of the under surface of the prothallium, just back of the " sinus," we may see
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