Wonderful black and white drawing of a tadpole with legs that would be a great science picture. Captured between tadpole stage and adult frog, this frog picture is unusual and interesting. Best of all, it is in the public domain and can be easily downloaded. It was drawn by Jessie Wilcox Smith (1863-1935) and included in the 1916 work The Water Babies.
This image is copyright free and in the public domain anywhere that extends copyrights 70 years after death or at least 120 years after publication when the original illustrator is unknown.