The nature of a mysterious jelly found outdoors has caused much debate.
It is often found simply as a clear gel; see
NS3678 : A moss, with "mystery jelly". In other cases, clusters of small round black objects are found associated with it, as illustrated here. As can be seen here, there were pinkish smears of blood on the surface, and even some remnants of blood vessels; this provides compelling evidence for an animal origin.
It was lying on a footpath, next to a puddle, in (as usual) a place where frogs can be found. Many have suggested that this material is from frogs taken by predators, and this seems to be the correct explanation. My photo shows what are apparently the convoluted end-parts of the oviducts).
Over time the substance absorbs water, becoming more transparent, and swelling a great deal (consider the volume of a mass of frogspawn, compared to the frog that lays it; it is therefore not surprising to learn that after frogspawn is laid, the gel around the eggs expands in water). The original compact mass often ends up broken into scattered blobs, as illustrated at
NT3707 : Pwdre ser - a slime mould? (note the black eggs there, too); the "clear gel" image (see link in second paragraph, above, and also
NS4179 : Mystery jelly in woodland) is a still later stage, where all the eggs have been eaten (this is perhaps what results in the gel's ending up in scattered pieces).
The black "dots" are the eggs. If these look smaller than expected, it is because the round blob of jelly that usually surrounds an egg in frogspawn acts rather like a lens. The clear jelly that would normally surround them occurs here separately, and in an unexpanded state. Because, in this case, they were not laid as frogspawn, the two components were found uncombined.
Other natural jelly-like substances are sometimes encountered outdoors; see
Link for a partial list.
Various other common suggestions about the identity of the kind of jelly shown in the present picture can be dismissed fairly easily: slime mould (not very similar anyway, but the plasmodium of a slime mould engulfs vegetation, flowing over and around it, in intimate contact; it is never simply lying on grass in such a way that it could be picked up as a separate object); jelly fungi (these grow, directly or indirectly, on wood); cyanobacteria such as Nostoc (these are photosynthetic, and therefore not colourless).